Bv or std?

I had unprotected sex about 3 weeks ago. I got my period a little over a week later and I've been off it now for 5 days. About a day or so after I had sex I started to have a thick yellowish discharge with a foul smell. Throughout the duration of my period I could smell it when I removed my tampons as well. After my period, I'm still experiencing foul smell discharge. Also, the smell is stronger right after sex. This may be unrelated, but I'm catching a cold as well (Congested, itchy sore throat, sinus headache.)

Basically my question is, if I have an std would symptoms show 2 days after or is this just bacterial vaginosis? Thanks so much ladies!