16 and scared I'm pregnant.

I went to the gynecologist a couple weeks ago to find out about birth control. She said she could give me the patch, but not until I started my period. Which should be around the fifth of the month. Well I've been waiting since then, and now it's the ninth. A few days ago I started to feel like i was going to start. I was getting acne, crampy, and hungry. My boyfriend and I had sex a couple days ago and the condom broke. Since then the symptoms went away.
I can not have a baby. The whole reason I went to the gynecologist in the first place was because my mom is 150% against teen pregnancy. I know this sounds horrible, but I am pro choice, and if that's what it comes down to I need information on finding a way to have that done.
The worst part is, my mother is counting the days I'm late right along with me. She's waiting for me to tell her I need to go get my birth control, and I'm scared she'll start to catch on pretty soon. I promised her I wouldn't even be having sex once I started birth control, let alone before I even got it.
I'm just really scared.