Pregnant? Should I test?

So I was on birth control for 3 months (depo) with my current boyfriend. we had sex unprotected the week i was suppose to get my second injection. Which I'm not too concerned about. We broke up for about a month, and then we talked it out getting back together. We've had unprotected sex and he always pulled out but I won't lie sometimes it would be last minute. To top it off we would continue after cause he can go multiple rounds. Of course we clean up just a little but I mean there's not really a fool proof way to clean. Anyway since I've been on Depo and off for 4 going on 5 months I havent gotten a period. The 3 months was depo I wasn't concerned but being off it for a while now I still havent gotten it. I do get random moments of nausea but it's usually later in the day or late at night. But now my nipples are really really sore and sensitive. When I used to get my period my boobs would get sore, but never my nipples. So not having a period and the sore nipples really make me question if I should test or not. As well as since I dont/havent gotten a regular period I cant be like "oh I'm late let me wait 2 weeks from now before I take a test". What should I do?