Q&A: Semen Allergy: Could I Be Allergic to My Boyfriend’s Semen?

When my boyfriend and I have sex and he ejaculates inside me, I get a really bad burning feeling in my vagina. It gets red, too. It just feels very irritated; this only started recently. Assuming we’re STI-free (we plan on getting tested next week), could I be allergic to his semen?