incident occurred on august 18th. did not cum inside but had about 5 minutes of penetration. got her the pill the next day, took a pregnancy test ten days later and came back negative. couple of days later, she got her period. this period was much heavier than usual and lasted for about a week. the next month she got a very unusually light period on the 27th of september . worried, we took a handful of pregnancy tests which all came back negative. since then, she has been occasionally feeling nauseous, no vomit though, tired, her nipples have grown slightly. we took another test about a week ago and it came back negative, she should be getting ehr period at the end of this month, october. also, about a week ago, she had thick eggwhite like cervical mucus and had cramping on one die. is this due to ovulation? should we still be worried about pregnancy? please help.