VERY WORRIED need answers

Patient: I have had anal sex about 26 days ago…he did not ejaculate or slip forward he only started pre cumming after he was away from me and it only lasted for 2 mins ..then 2 days after I had nexplanon put in and my obgyn docter tested me for pregnancy and it was negative then 10 days later I took another test…negative…then 14 days after having anal sex I took 3 tests and a digital pregnancy test and all negative should I be worried? right now i am on my period the blood is bright red and some tiny clots here and there but not as heavy as a heavy period i have had it for 4 days now going on 5..can nexplanon make my periods lighter? should i be worried about pregnancy

Doctor: Per se, anal impregnation of spermatozoa should not be able to cause pregnancy unless some of it finds its way to the wo mb.An unprotected intercourse results in pregnancy only when a woman is in her so called “Fertile Period”. The fertile period of a woman is determined by analyzing her menstrual cycle with an ovulation calculator or fertility chart. Normally, the menstrual cycle is a 28 day cycle. During the 14th day after a period, the ovum is released. This process is called ovulation and the days 12 to 16 days after a period are said to be a woman’s most fertile period. Ovulation may not occur at a predictable time in the menstrual cycle, however. A number of factors may cause an unexpectedly early or late ovulation, even for women with a history of regular menstrual cycles.A pregnancy test attempts to determine whether a woman is pregnant. Markers that indicate pregnancy are found in urine and blood, and pregnancy tests require sampling one of these substances. Most chemical tests for pregnancy look for the presence of the beta subunit of hCG, or human chorionic gonadotropin, in the blood or urine. hCG can be detected in urine or blood after implantation, which occurs six to twelve days after fertilization.Implants are hormonal in nature and they may alter the bleeding pattern. Please consult your gynecologist for personalised advice and care.