Did I ejaculated or not? Help.?

so my girlfriend and I had unprotected sex yesterday. after a few moments I felt a tingling sensation like I'm almost going to ***. so I pulled and let the feeling disappear for a few moments. Then went back inside. then I pulled again to see a tiny chunk of semen on a "bush" I don't know if it's mine but I didn't ejaculated at all. But I swear I didn't *** inside or came at all.. I'm really scared. after that moment I saw a little bit of trail marks on my shirt.. after a few moments when we where done I check my underwear and a saw a few marks of *** and my pre-*** starting to come out. I think I only felt a dry orgasm and later on after we finished I came only a little bit. no blue balls or anything..

What do you guys think..? I'd like to think that it came from her.. but the positing of the chunk of whiteness is off..

And when semen comes in contact with water it turns into a chunk of whiteness. What do you call that and can it happen even without water?