What could be going on?

Kadie • :)
I made a post earlier but left out a few details that might help figure out what's going on. I had a very short, light period on January and on the last day I had sex. Then in February I was a few days late and had my period. It was short. But after that I had been sick, back hurting, and boobs very sore. So I took a test and they have all been faint positives. I was suppose to start on the 15th and I only spotted once today. Does anyone know what this sounds like or what could be going on? I tried going to the health department yesterday but they wouldn't test me due to not missing a period so I could be preferred to an ob/gyn