I do think it is very unlikely for anyone to get pregnant from fingering. Normally it takes a penis inside the vagina for pregnancy to occur. It 'could' occur theoretically but is not that common. Do as anniebrooke says and I wouldn't be terribly worried. Periods are late frequently though and typical reasons are changes in routine, illness, stress, weight gain or loss, or just a blip on the hormonal radar. 2.5 weeks after fingering, you can take a pregnancy test. That's how long it normally takes to get a positive result if pregnant. I'd buy some condoms just in case as this is getting closer to having actual intercourse and I'd demand your boyfriend wash his hands and not finger you with ejaculate on his hand.