Help! Don't know what's going on

Kadie • :)
I've not missed a period but I keep getting faint postive test. I went to the health department and they wouldnt test me due to not missing my period. My top 2 test are mid afternoon so they aren't very dark but there. My last 2 are morning test and they are a little darker. I haven't been sexually active since jan 18. Anyone experienced anything like this at all?