My most fertile day was Saturday, so my husband and I had intercourse Saturday and Sunday and then again last night. I have been feeling a bit nauseous on and off and have been having mild cramps. Also, there has been a little pain in my left abdomen it isn't all the time though. My back has been hurting as well. Today my head started to hurt too, but it only hurt for about an hour and then it stopped. I don't know if it would be too soon or not for me to be pregnant? My period isn't due until the end of next week.