Yeast Infection or STI?

So I had sex for the first time last Saturday night, was very unplanned and so didn’t use condoms as I didn’t expect to get laid then😂 I did miss a few pills that week so went and got the morning after pill the next day. Now I’m getting some clear/light yellow discharge that doesn’t smell at all, but I am a little itchy with a bit of redness round my vulva. I’ve had loads of yeast infections before but now STI’s can come into the equation I start to panic😂