Pregnant?

So I had my period or what I thought was my period. However it’s was really light and only lasted four days 3 of those were mostly spotting. My husband and I had unprotected sex on September 1st (the day before my ovulation making it a high percentage) and a few other times during the month. I’ve been feeling extremely nauseous to the point where I can’t eat, excessively tired and sleep pretty much all day, I get tired easily and get headaches almost every day. I took a pregnancy test after my “period” and it came back negative. That was about 2 days ago and I’m still feeling this way should I retest?