Relationship problems

So me and my boyfriend have been currently going out for about 6 months now but we have been on and off talking for about 3 years in the past he has put me through a lot of crap he played me a few times and of course I took him back but now were going to strong and all of a sudden I start thinking of the past I'm not sure f I have trust issues and I'm afraid if I bring it up it will be an argument I jus don't know how to cope with the past can someone help ?