Am I pregnant? Can semen survive outside of the penis-testes and vagina?

I'm terribly afraid. I'm fifteen and fear that I could be pregnant. I was stupid and my boyfriend and I got ahead of ourselves. We lost our virginity to each other and had unprotected sex occasionally. He never ejaculated inside of me but did next to me. I can't remember but think I may have inserted my finger into my vagina with a very small amount of his semen on my finger. Which I hope I did not, considering that is terribly stupid. Could the sperm have survived and reached my eggs? Lately whenever I eat my stomach feels uncomfortable very briefly, sometimes from gas. It does not feel nauseating. I'm also very fatigued. My period was not delayed very much. I'm so stressed out and very scared. I'd like opinions and website sources. Please help.