NEED ADVICE!!

Hey, so this may be a bit long, but I really need some advice.

So I'm 18, and my fiancé is 24. We have broken up and gotten back together twice over the last year and a half. Recently though I've been having a lot of doubts as to whether or not I'm in the right relationship for the right reasons.

I do love him, but I am scared of being alone, and I worry that that's why I'm really with him. Also, because I'm so young, I wonder if maybe I'm rushing into this, if maybe I should explore the rest of the ocean before i settle on this one fish, you know?

Something that makes my decision even harder is that him and I both recently moved to Texas and are staying with my mom, so he doesn't know anyone out here. So if we broke up, what would he do? I don't want him to be hurt or inconvenienced like that. Oh, and im4 days late for my period, so I also might be pregnant.

Please, somebody help me decide what to do. I'm so lost and confused right now.