Hello About A Month Ago I Met A Woman At

Hello

About a month ago I met a woman at a party and later on had unprotected sex with her (so stupid of me, I know) Since then I've have been quite worried and planned on going in for an STI screening after 2 months of the intercourse. Last night, while in bed, the foreskin on my penis had a light itch to it, so I rubbed it/pinched it since you can't really scratch a soft penis. This morning while peeing I noticed that there's a decent sized bump on the foreskin, right where it folds (I'm circumsized) it doesn't seem to itch if I don't touch but I can still feel it whenever it rubs against my underwear and then there's just very light itching in general all around the genitalia. I'll be going for an sti screen this Tuesday (roughly one month since the intercourse) instead of in another month. Should I be worried? Any feed back is helpful.

Thank you .