Light period after sexual stimulation with clothes on

Hello everyone

I know this is a stupid question. Everything that I know about sex education tells me its not possible, but I still want to get other opinions. I had something like dry sex on January 22. . I was fully clothed ( jeans, under wear and a pad), he had on jeans and underwear. We fooled around on the bed for a little. I think he did pre-cum but no full ejaculation . I didnt notice any wet spots to my knowledge. I didnt think much about it until my period was really light. It came right on time( February 18). When i say light I mean the color was normal blood red the first day. The second day it finally went to the darker period red and picked up to become more heavier. The flow seemed normal on the second day. Then the 3rd though 5th day it returned to light ( which is actually kind of normal for my cycle). I have had some lifestyle changes that could affect my cycle. I recently ( January) switched from a vegetarian to a vegan. ( I was eating fish, but I went to not eating any meat at all as well as other things). I also joined a health club and increased my workout a little more. So I do suspect that could be part of the problem.

I have taken 5 pregnancy test ( 2 first response and 3 clear blue easy ( most recent one this morning). I went last week to the Gyno for a pap and i did ask him about pregnancy and he said my cervix looked normal. Im just wondering has anyone ever had anything like this happen to them as far as their cycles going really light and also what are the risk of dry sex with clothes on. Im sorry if this sounds like a dumb question, but i honestly just dont know the answer. The internet gives so many conflicting answers on dry sex with clothes. Some sites say yes you can get pregnant his way and others say you cant. Some say you can only get pregnant if the clothes become soaked in semen. While other say that sperm dies while try to get though clothing. ( this sounds like the more likely answer, but its hard to say). I was too embarrassed to ask my doctor about this specific situation.