Help meee😭😭

I have only had vaginal intercourse with one person (my first )I have only had receiving oral from one other person one time. (This was after my now ex boyfriend)I got chlamydia and both of those partner‘s test came back negative. How???

My first got tested and treated anyways and so did I, we recently had sex again and the condom broke now I’m scared I might have it again.

I found out I had it 2 1/2 months ago.