I gave my boyfriend a blow job for the first time almost a week ago and i still have a sore throat and coughing a lot. he has no std what happened?

Probable aspiration: It's possible you may have got some oral secretions (saliva) into your airways from this activity. Your reflex would be to cough -and I suspect that has made your throat a little bit raw and painful. If you don't have fever, troublesome cough, or significant pain - then I expect you to get better on your own. If you have any doubts though, see a doctor. They can check the back of your throat/lungs