Am I pregnant?!?

I've been having sex a lot recently with a guy I'd love to call my boyfriend but it's way more complicated than that. I took plan b about a week after my period. That was 3 weeks ago and I've already had another period. Now I'm spotting and I've been throwing up ( I'm not sure if that's because of nerves or not tho).

Anyway. Long story short I don't know if I'm spotting because of taking plan b or if it's because I'm pregnant.

Anyone, please help.