Having problems with my bf.?

me and my bf apparently fight a lot we have been together for 4 years and this feb he broke up with me like 3 weeks before we got married. he found one of his ex on fb which was his firs love and he had feeling for her again HE went out for a month and found out she just wanted revenge wanted to get preg and blame it on him the thing is she was sleeping with 3 other guys and my bf never slept with her and she got mad one day and just broke p 2 weeks later she post up on fb that she was preg my bf could not believe it i was hurt so i dint talk to him for a bit then he asked me out to lunch and we talked and he said he was sorry if i could ever forgive him and i though about it it took me time and i said ok i will but now were back together and just this constant fighting and nagging from both of us but we end up talking about it but the proses is painful. is it still worth being with him his Friends keep telling me that he has a surprise and that he really love me and that his sorry and this are guys who never talked to me until everything happen and they came on their own and told me this what should i do