Should I go get tested?

So my long distance boyfriend and I had sex a couple days before my period. When we first had sex it burned but after that it was fine. Got my period everything was fine. Now that my period is over I still am having some light brownish yellowish discharge. I love my boyfriend and I don’t think he would cheat on me but should I go get STD tested anyways? I’m also on the IUD if that affects anything!