If all they are doiong is hissing, swatting, chasing, even growling and "fighting" is alright. That is TOTALLY normal. I guarentee the vast majority of cats do this. They are FINE. Bloodshed is when you need to worry. I think they will be fine, just leave them be. You really need to get the girl spayed becuase that will make a huge difference. Plus, when she goes off for the day to be spayed, she is going to come back home smelling completely different and you may be back at square one again (have to reintroduce them all over again). You MIGHT, not necessarily.
But seriously, they are fine. My cats have been together for years and they still get into each others space and growl, hiss, swat, chase and even "fight" once in awhile. If they took treats right next to each other they are fine. Keep doing this everyday. Play with them together.
Also, expect a "fight" from them too because at some point they will need to determine who is alpha in the household.