help...

I have pretty much convinced myself I can't get pregnant. During my fertility window I had sex 3 time and than 3 times after it. We did not use a condom and I'm not in birth control. I was suppose to start my period yesterday and haven't. Ive had all the symptoms of starting such as craving sweets, getting acne, a little bit of cramping, and crazy mood swings, and I've even been extremely tired. I don't know if maybe because my SO thinks I am is why now i feel queasy and feel like I go to the bathroom more or what. I'm scared to take a test and just need some advice. Thanks.