Hello, I have gone through the query and understood your concern. Pregnancy is not possible in the current scenario since you had a menstrual period after the intercourse. Moreover your cycles are well protected due to the hormone contraception you are taking. Your symptoms suggest hormone disturbance. This can happen with sudden weight changes, stress, infections, cysts of the ovary and use of certain medications. I would suggest a proper clinical evaluation, blood counts, urinalysis and a sonogram of the pelvis preferably in the trans-vaginal route. Further management can be planned accordingly. Hope this helps.