Hello and welcome to HCM
does not take place during menstruation
and few days before and after menstruation.
The most fertile days are days around ovulation i.e. 14 days before a menstrual cycle.
The abdominal discomfort that you are facing could be due to some other cause and not due to pregnancy.
In case of doubt get a pregnancy test to rule out pregnancy.
Thanks and take care
Dr Shailja P Wahal