Half Virgin?

Hi! I'm new to this app and it's so helpful so far and I'm loving the community:) I'm 17 and my boyfriend is 19. I am a virgin, but I have done everything but sex. This week we fooled around and dry humped (I guess that's what you would call it?) and we got a little too into it and I almost lost my virginity...I was talking to him about it and he said that I have nothing to worry about because he knows when he's close to cumming and he would never put me in a dangerous position of being at risk of pregnancy (that is my biggest fear as a 17 year old girl in high school) but nonetheless he did almost penetrate and there was outside contact between our genitals. He was not wet , there was no cum, I was currently at the very end of my period where I didn't have to worry about flow. We both are std free, that is not what I'm worried about, but should I be worried about pregnancy in this sort of situation? Or am I just being a paranoid teenager? Any advice or words or wisdom would be fantastic!:) thanks guys❤️
Oh and also if I do decide to have sex, what's your guys advice to best avoid pregnancy without having to go on pills for birth control. How reliable are condoms alone?