Hi I Am 26 And My Husband Is 34 We

hi i am 26 and my husband is 34 we have same blood group AB+ . i had abortion in 6 and half month pregnancy one year back . i had irregular period just 3 months back so took non pregnancy pills 2 packs and this month. i got periods on 16th June so i left taking tablet and try to have sex during ovulation time but i got periods today that is 19th july. what was the reason i not conceive? please suggest me