Ladies, your thoughts please?

After an awful relationship that ended up in me being assaulted by my daughters father I decided to leave him....for the last couple of years I had abstained from dating and sex all together but recently this past April I started sort of seeing someone. This guy is someone that I have known for over 10 years...we always liked each other but our lives always lead us in different paths but we picked up easily. He told me that he had a vasectomy and we had sex without any type of protection. But having had bad experiences in the past with other people I decided to not completely trust him and I purchased a plan b pill. I had some light spotting which stopped and my period came on time when it was due. We’ve hooked up a total of 5 times. Just this past weekend was our fifth time and on the following day I started bleeding like light period bleeding and it has continued up until current day (it’s been 3 days since)

I took a pregnancy test and it came back not pregnant...what are your thoughts? Could I be having a miscarriage? Has anyone had a similar experience?

Thanks ladies