Welcome to HCM.
Going to Gym may not be the reason for not getting pregnant.
You need to consult a gynecologist or infertility
specialist. You will need an ultrasound
scan to see if there is any problem with your uterus
Your husband will also need to get his semen analysis
done to see if he has any problem.
If both of you are perfect, then you can get pregnant by timing your intercourse between 12th to 14th day of your menstrual cycle. Avoid gym after intercourse till your next period. If you miss it then confirm pregnancy
by pregnancy test and if pregnant forget gym till you deliver, otherwise you can continue with gym.