If you have sex 2 days after menstruation, how long will it take for you to fall pregnant?

Bad cycle timing. Have sex on days 13-15-17 of your menstrual cycle, this is the frequency and timing that is most effective. You need the two day interval to build up the sperm count.
Low risk time. Pregnancy always a chance, but not likely at that time. If going to conceive from that event, check pregnancy test 2 weeks after. If trying to conceive, "fertile time is mid-cycle, usually around day 10-14.