someone please help!!

so my periods coming up in 6 days and I just noticed these blue veins pop up on my breasts and down to to my nipples. the last time I got sexually active was like 2 weeks ago and all we did was grind on each other naked. he didn't enter me at all he just brushed my other parts. he ejaculated an hour before that but he probably precummed during the grinding.this was a few days after my menstrual cycle. I don't know if I could get pregnant by this or not and I don't know if the blue veins can be a sign of pregnancy or pms. I'm just worried his precum would find its way inside my vaginal opening.