Sexually transmitted infections

I've had sex with 6 people and I've been with my boyfriend (who is clean) for a year now. I've never been tested before and recently I've worried that I might have an STI that I don't have a clue about, since many of them do not have symptoms. 
But... I'm scared to get checked out because I feel like my boyfriend will think that I've cheated if I have any STI's😓