Hi,
My wife usually has irregular periods. In the month of August her period was late by 16 days. However, in the month of September her period started on 16th of September. Now, the period did not start in the month of October. Last week we visited the doctor who said my wife is pregnant. However, she suggested to go for ultrasound. Last evening we went for the ultrasound. As per the report, the baby is in the initial stage and has not grown enough as per the timeframe. They said since my wife has irregular periods the pregnancy should be at the initial stage. However, they also mentioned that they cannot ignore this fact that the size of child has not grown that much. They have given some medicine and asked to get ultrasound done in another 3 weeks just to check whether the child growth is fine as per the timeframe since my wife has irregular period. I am quite worried. Please suggest if this is common in girls with irregular periods

I don't want to increase your worry. I have to say that I didn't completely understand your post. So, if my post doesn't answer your question, it's because I didn't completely understand what you were asking.

It's very possible that your wife is in the early stages of pregnancy. If that's the case then ultrasound isn't that reliable. Remember, your wife has irregulate periods, so pinpointing when she conceived, and how far along she is, can be difficult.

Here's the part the worries me. They gave your wife medication after her ultrasound? What medication did they prescribe? What is this medication supposed to do? Why did they prescribe it? Do they know that your wife's periods are irregular?

The only issue with an irregular period is not being able to pinpoint when conception occurred. That means that any tests done, like ultrasound, could be offf, since there's no way to know how far along she is, other then by what's on the ultrasound.

Don't panic. Wait the 3 weeks, but do figure out what the medication is for.

They use last period as a baseline to compare the growth of the fetus. So without a good baseline to go by, they have nothing to compare.

What type of medication did they give her and what for ?