Risk of pregnancy from indirect contact with precum?

Is it possible to get pregnant from dry sex? Four days after the last day of my last menstrual period (7th cycle day), my boyfriend and I dry humped. I was wearing my panty (with panty liner) and he was on his brief and shorts. No ejaculation happened during the humping session, but according to him, there was a small precum inside his brief. His shorts was not wet upon checking. He also fingered me during the hump, but I'm sure that he has no semen on his fingers because he has not touched his penis prior to touching me. He, however, ejaculated on his chest, 10 minutes after, with me sitting beside him on our bed, and already completely wearing my clothes (shorts and top). Am I right to assume that no pregnancy would occur from this right even if I was wearing just my underwear and he was just on his brief and shorts? Thank you so much.
PS. Took a pregnancy test 2 weeks after our last contact, it was negative. Would it be reliable to take a test if I took it 2 weeks after our dry sex, even if I haven't missed my period yet? Right now, I am experiencing cramping and sore breasts (like my PMS last month), but this day, I feel like I want to vomit (but didn't really vomit even if I try to). I am just really scared and anxious so that might be why I was so nauseous.
My usual cycle lasts for 29-32 days (with 29 as its most usual length).
Another one: if I got my period on that cycle, it means that I did not get pregnant, right? Last September, my boyfriend and I also dry humped. He was wearing his brief but I am not wearing anything. If my app is right, that should be 7 days post ovulation. Got my bright red period, which lasted for 3-4 days, 8 days after the contact. Also took 2 pregnancy tests (1 week and 2 weeks after my period), just to be sure and they are both negative.