Could i have an sti? had sex 2 months ago. with a condom. but halfway through he took it off & put a new one on. im showing no symptoms. but im terrified of having an sti and looking up symptoms online. i dont wanna have an sti. help?

Very few things in this world are "impossible"! .. but, that doesn't mean they are likely. From what you described, I think the chance of you having an STD are slim. One encounter and I believe you don't know if your partner had an STD. Most of the time he was wearing a condom... (yes its possible, if he had an std, switching condoms allowed possibility), If you want to be positive get tested.