I have been spotting and sore and burning after having ?

I had with my boyfriend a few days ago after not having for a few weeks because I have been pretty sick. The next day I began to have spotting and it has lasted for a few days now and my is also sore and I am having a burning sensation. We are both monogamous and live together so I do not think it is an STI. Does anyone know what the problem could be? It is very uncomfortable. Oh and we used a condom as well.