What Causes Heaviness In Lower Abdomen After Periods?

helo dr
i had sex when my hubby was leaving out of station 1 week before,,,
we are newly married couples,, we were using condoms for the past weeks of our marriage?? planned to consult a gynecologist shortly.. but he is out of town now,, not interested to conceive now?? got my periods also after 4 days of sex with my partner??
but feel my lower abdomen to be heavy since my periods??