Hello, I have gone through your query and understood the concern. It is possible to conceive after a delivery or abortion without attaining a menstrual period. This is enhanced with lactation, though it acts as a natural contraception by tending to delay ovulation, the ovulation which happens by chance if often ignored. You have to get a proper clinical appraisal, a sonogram of the pelvis preferably in the trans-vaginal route, a pregnancy test and plan further management according to the result. You may not have any specific symptoms during subsequent pregnancies and also, the fetal movements can be perceived earlier. Hope this helps.