They fought a lot?? Fighting isn't very good, are you sure they are not both males? Usually a male and female don't fight, but I don't know.. ? I would seperate them right away, fighting is never good.. Do you have some pics of them?
To answer your question, though, you cannot be sure that they've mated unless you actually witness the mating, or it's been so long that the female starts laying eggs. However, you can look for mating behavior, which can include any or all of the following:
tail vibrating - the end of the male's tail vibrates so fast that it makes a really loud buzzing noise if it's up against something
vent licking - after breeding, the male will lick his vent area and hemipene clean. The female may also lick herself
stalking - the male stalks the female for awhile sometimes before breeding
But once again, the fighting isn't good by any means. Just beacuse they don't seem to fight anymore, you cannot watch them all of the time, and they need to be seperated so that one doesn't get severely injured.
When they were fighting, were both of them vibrating their tails at eachother? That is one indication that they are both males.. Although, I do not think two males would last a few days living together, so I am thinking that's not the case..