Dumb Question but ..

I was with my boyfriend and I was sucking his dick and I tasted the precum but he didn’t cum. I tasted the precum once but nothing after that. I just got the implant yesterday but before that I was on the depo and I got the implant the due date of the shot. Anyways, I’m currently spotting but not a lot so I rode him for 10 minutes max. Technically I did have unprotected sex because we didn’t use condoms and the implant didn’t fully protect me yet but I’m wondering , since I tasted the precum once when I was sucking his dick, could he have precame in me as well because he didn’t cum at all, just pre. Also, since I was on the shot and it didn’t fully get out of my system AND I just got the implant , am I considered somewhat “safe” or should I just wait it out and take a test

Also, should I take a plan b or is that too many hormones ?