Thanks for writing to us.
It seems that you have a muscular injury
of the chest. Since you are pregnant, the beswt way to treat is to take a mild pain killer like acetaminophen
and do a hot fomentation in the area. You can apply a local analgesic
gel also for relief. It is likely to subside in 2 weeks.
I hope this information has been both informative and helpful for you.
Dr. Rakhi Tayal