Hello ma'am. The possible cause of your baby stretching is colic.

It is very normal and will stop on its own.

The cradle cap looks like waxy pink or orange scales on the scalp. They can be mild or can grow so thick it looks like your baby's wearing a cap. Cradle cap generally shows up in the first month or two but can pop up anytime within your baby's first two years.
This is a form of seborrheic dermatitis, which is also responsible for dandruff in adolescents and adults. The most common cause is yeast that grows on everybody's skin but prefers to live in greasy areas like the scalp. Babies are prone to cradle cap because mom's hormones that are still circulating through their body send oil-producing glands into overdrive.
How to help: For mild cases, just use a gentle shampoo to wash your baby's hair. You can also try massaging mineral or olive oil into the scalp and then washing it out. It's okay to next use a soft-bristled brush or your fingertips to brush out flakes, but be gentle.
For a severe case of cradle cap, your pediatrician may recommend that you use a medicated anti-dandruff shampoo.
Cradle cap may look kind of funny, but it's not dangerous.

If you think the stretch is not normal, take a video while your baby stretches and show to a paediatrician while discussing your concerns

It could take up to 1 year or more for the adult replacement to come in

The DPT or Penta injection is usually given deep into the muscles. One of the side effects is swollen/red injection site due to some mild bleeding into the muscle. It needs to be properly managed so it does not become infected and turn into an abscess. The simple treatment is to apply ice pack or small piece of ice block wrapped in handkerchief on it intermittently for the first 2 -3 days. It will go down. Also avoid too much handling of the affected limb as the site is usually sore. It should resolve in 2 - 3 days but if it persists and/or become bigger and soft with pus inside - that is an abscess, please go back to the hospital or health centre so that it can be drained and additional treatment including antibiotics will be given.

You can also give paracetamol for pain.

Kindly see a doctor to know what type of rashes the child has and for the right treatment to be instituted. Diaper creams like vaseline, shea butter, sudocream, zinc oxide creams are usually preventive but with obvious rashes, kindly see a doctor for proper evaluation and treatment.

For mild cases, just use a gentle shampoo to wash your baby's hair. You can also try massaging mineral or olive oil into the scalp and then washing it out. It's okay to next use a soft-bristled brush or your fingertips to brush out flakes, but be gentle.
For a severe case of cradle cap, your pediatrician may recommend that you use a medicated anti-dandruff shampoo.

Most cold and cough both in children

Do not burst it ma, the pus and swell are normal signs of BCG when given to baby, it will resolve on it's own.

Your baby is suppose to be on exclusive breastfeeding. Do not introduce formula just because you resumed work.

On your baby throwing up after feed, it is reflux or more properly called Gastro-oesophageal reflux. It basically means food tend to return from the stomach back to the gut....which is the opposite of what is right way.

Also on farting alot "It is normal end-products of the digestive process and some of bacterial in the intestine on the waste causes the gas production. It is nothing to worry about

The DPT or Penta injection is usually given deep into the muscles. One of the side effects is swollen/red injection site due to some mild bleeding into the muscle. It needs to be properly managed so it does not become infected and turn into an abscess. The simple treatment is to apply ice pack or small piece of ice block wrapped in handkerchief on it intermittently for the first 2 -3 days. It will go down. Also avoid too much handling of the affected limb as the site is usually sore. It should resolve in 2 - 3 days but if it persists and/or become bigger and soft with pus inside - that is an abscess, please go back to the hospital or health centre so that it can be drained and additional treatment including antibiotics will be given.

Your baby is probably having colic, it should resolve on its own without any treatment. It usually starts a few weeks after birth and often improves by age 3 months. By ages 4 to 5 months, the majority of babies with colic have improved.
You may however give Infacol Colic Relief Drops for relief but note that it does not work for every baby.

Maintaining a healthy diet during pregnancy is very important.

During this time, your body needs additional nutrients, vitamins and minerals. In fact, you may need 350–500 extra calories each day during the second and third trimesters.
A diet lacking in key nutrients may negatively affect the baby’s development.
Poor eating habits and excess weight gain may also increase your risk of gestational diabetes and pregnancy or birth complications. Put simply, choosing healthy, nutritious foods will help ensure the health of you and your baby. It will also make it a lot easier to lose the pregnancy weight after you’ve given birth.

The straining is nothing to worry about as long as the stools are normal

You don't need to go empty stomach just make sure you take water.