Scared

I haven't had my period since The beginning of December. I've never had a normal cycle. It has always been irregular but not this bad since I was in middle school. I am 3 years out of high school now. I have sex almost daily with my fiancé some times he finishes and sometimes he doesn't. So I don't know if I should take a test or not. I'm getting myself so worked up over this. I have an a miscarriage before about 1 1/2 ago now. So I'm always scared if I don't get the proper help with pregnancy I will happen again. I just don't know what to do