Pregnancy test after abortion.

So I had an abortion exactly 4 weeks ago. I'm still not on birth control because it usually makes me feel sick ( I should probably look at other bc options ) but anyways.. I'm not exactly sure when I should start my menstrual cycle again. I've read it could be 4-8 weeks. This week I've been feeling a little off, tired, and having to pee a little more than usual. Automatically I think maybe I'm pregnant again? Yes, I've had unprotected sex since my abortion. I took a test and it has a faint positive line. I'm not sure if it's hormones from before. Should I wait and take a test again in a few days?