I'm hoping my mind is playing tricks on me

Three weeks ago, I was due for my period. My boyfriend and I noticed some blood while having sex, so we both assumed that was it. However, I didn't notice any more until a week later but it was light and lasted three days. The past few days, I've been weirdly emotional and sick to my stomach. I've also been more tired for no reason. I haven't been stressed or doing/eating anything different. I took a HPT after the three days of light bleeding and it was neg. My periods are always regular and I've never had an issue before. I don't have health insurance right now so a blood test isn't really an option. Any advice would be great. Thank you.