Dear Radhu:
Congratulations!
Let's follow the logic here....
You are pregnant! That is wonderful. You are, however, not only responsible for your life now, but for the well being of your growing child. You also have a dental problem. You know that since you are in pain. ...and what do all the smart "they" tell you? "don't go to the doctor"????
It is absolutely true that any elective dental treatment should be done in the second trimester. At that time, all the major organs of your fetus are formed and the potential for damage is limited. Also, if you are treated in the third trimester, the stress of the treatment might induce premature birth.
However, you are not looking at elective treatment at this point. You have a problem which has to be addressed immediately, if only to obtain the proper diagnosis.
So, here is what to do...
Go to your dentist and have your mouth looked at. Have them take an X-ray of the problem teeth. The more current digital (computerized) x-ray systems produce negligible radiation (you get more radiation going in the sun). Make sure that when the X-rays are taken, your belly is covered by the lead apron and ask, before you go, whether the X-rays are digital. Most contemporary offices are digital.
Ask the dentist if the problems can wait a couple of months. If they can, wait until your second trimester and have the work done.
This IS VERY IMPORTANT! You need to be healthy throughout the pregnancy for the sake of your baby. ...and trust me, as a father, I can tell you that after the birth, you will NOT have time for the dentist.
Don't forget to also ask the dentist about your oral hygiene and make sure that you are brushing and flossing very well.
There is a clear link between poor oral hygiene of the mother and low birth weight of the baby.
Keep your health at an optimum first.
Best wishes for an easy pregnancy.
Dr. Zev Kaufman