'Accidentally'? Deal with this asap, he deserves better than getting stringed along by a cheater. And return the earrings.

I gotta keep it real w/ you OP. There's a lot to unpack here about your overall character in regards to relationships. I don't know you as a person and in other aspects you could be an exceptional person bc the world isn't that simple, so I'm not judging you overall. But the word "accidentally" only goes as far as the pregnancy, you're seeing someone else and you said boyfriend so unless you have an open relationship then you're cheating. I would refrain from using the term "accident" about anything. Your actions are intentional, the consequences were an "accident." the "i can't tell him it's his because..." implies that had you slept together already, you would lie and say it was his if you knew otherwise simply bc you could get away with it. I think you need to search internally within yourself and realize the way you are treating others and the consequences of your actions, not just pregnancy but the damage you are causing others as well. you're being somewhat reckless with the hearts of others and they'll have years of damage due to your selfish decisions. now again, you may be an amazing person otherwise, but this is a side to you that deserves some inner work. good luck to you.