Can semen residue get me pregnant?

Patient: My boyfriend and I had sex, using a condom whilst I had been on the combined pill for 3 days (started it towards the end of my period). He came in the condom. After about 30 minutes he rubbed his penis around my vagina. Could I get pregnant from this, seeing as there must have been semen residue on his penis? I am scared as I have a light brown, quite dense vaginal discharge, but this was my first time having sex and I finished my period only yesterday. We had sex yesterday.

Symptoms: Light brown discharge