My cycle is 33 days. My last period started December 26th. I ovulated the 14th and had unprotected sex. I had very light spotting January 23-26. Like only when I wiped. I was suppose to start my period the 28th and be on my last day today. I’ve only taken one pregnancy test and it was negative when I spotted. Should I retest and when? && is it possible to get negatives and be pregnant ?