I NEED HELP WITH CICHLIDS!!!!! D: PLEASE!!!!!!!?

I have 2 Rainbow Cichlids - 1 male and 1 female. They are in a 50 litre tank, and are on their own. I am trying to breed them, but it's getting really confusing. I am feeding them on bloodworm's and flake food, and sometimes they rub up each other, the male starts to dance around and they look like they are going to breed. But other times the male chases the female around, when he tries to get close she swims away, and the females fins are starting to look like they are getting bitten. I really want them to breed, so please can someone explain what is going on to cause this really weird behaviour. D: