Please help? BC + plan B

So at the beginning of last month I started birth control for the first time. While I was in the middle of the first week, I took plan B after sex just to be safe, really didn't even need to take it. My partner pulls out and I swallow every single time (never had one slip up) so there's not much to worry about (sorry for TMI).

In the middle of my BC pack I wound up switching birth control bc the first one was making me a crazy person. I also missed 2 pills and had spotting for a couple days after each missed pill.

I am also currently recovering from a really really bad UTI which I took meds for.

I'm now 15 days late, but starting to cramp a little and have sore breasts and a bad headache.

Is this because of all the hormones or could I be pregnant, even though he always pulls out?