Help, freaking out!

I'm 17 years old and sexually active. I have a bit of an irregular period at times but I completely missed my period for the month of April, I did have sex during that month. Me and my boyfriend always use a condom, and pull out, then afterwards we check to make sure there isn't a hole in it even though he always pulls out while still wearing the condom (just to be extra safe). But ever since I noticed I missed my period I realize that at night whenever I take off my bra I have blue veins on my breast, they go away less than a minute after but could this be an early sign of pregnancy ?? Or something else ?