What Are The Chances Of Pregnancy With Non Penetrative Intercourse?

On the 19th I did something with my boyfriend , we did not have intercourse, I am a virgin and want to wait . but I did get semen on my hand , I wiped it off some what good . about 20 minutes later I did not even thinking touch myself but not inside just at the way top so no where near the opening . I read online semen dies once dried so my hands were dry at the moment. I am just worried because I should be starting my period today or tomorrow. My menstral cycles are so irregular so I never know. I've done lots of research and read that I can only get pregnant if it was in my vagina and if it was fresh. I am very worried mainly because I also read you can have spotting 7-10 days afterwards and today I had a little blood in my underwear but I also read that's normal before a menstral cycle. I am having all of my normal symptoms of my period. I am very worried please help!