cheating?

So any one who hasnt been in a long relationship where they've grown completely attached to there SO probably wouldn't understand where im coming from but those who've maybe gone through this please let me know what I should do. So yesterday it was my birthday, my boyfriend picked me up we went to his house amd everything was fine. We were getting ready to leave to take me back to my house and i saw the corner of a condom wrapper in the sheets. (We have never used condoms!!) and i freaked out asking wtf where is this from and you think im stupid blah blah and he looked like he just got caught up. He looked guilty. But he just kept telling me idk where it came from repeatedly. Later he tried giving me a excuse saying our guy friend stayed over last night but he never ever mentioned that the night before. I didn't believe that. Im so hurt just thinking that he might've cheated on me but i love him so much and we've come so far in our relationship i cant just leave it. I want to know if i was trippin and or to believe him. Any of my friends would say to leave him but they don't understand the time invested and the love we share. He was crying on the way home when i was talking about im obviously not good enough and don't meet your needs etc i think he felt guilty. I believe in second chances but im so hurt i cant even think straight now im supposed to go on with my day happily? What a great way to end my birthday. Lmk what i should do.