Plan B- Did it do the job?

Is it possible to spot for a couple of months randomly after taking a plan b, and be pregnant? I’m just asking because If I hadn’t taken the plan B, I’d be going on four months pregnant. And my body has been feeling so weird for a little while, I haven’t noticed a need to pee more but I haven’t been keeping track. I’ve suddenly started craving things I had lost taste for a long time ago, and my stomach is almost always a little bloated. My periods are so light and short it’s too good to be true, so someone please tell me if I should be taking a pregnancy test and chill the hell out.