Should i contact my ex boyfriend or just leave him alone?

We have been together for over 6 years ,on june 12 (2 days from now) would be our 7th year but we just broke up this may . we have been on & off for all these years but i dont know if we will get back together this time.he just seems very happy and i herd hes being a slut ,and im happy too[& having fun ;) ] but he crosses my mind daily , i know he still loves me but it "hurts" him to be friends -___- anyway! should i say" hey happy almost 7 years?" or just send him a "heart" in a msg on fb ? its kind of killing me ,i miss him and it was my fault why we had to break it off this time. i have nothing to lose but i dont know if i should or shouldnt contact him HELP ?! i meet many guys at parties but none of them are good enough ,either they are stoners or have been around way too much thats orange county i guess :/ after meeting all these guys i just want him back and now value how sweet of a guy he is