Just keep pairing them until you get eggs or your set time frame. We do 3 or 4 days on and 3 or 4 days off depending on the cleaning cycle as it is easier to clean the males tubs while they are in with their girls and generally when you remove the male the girls tub needs cleaned as inevitably someone has peed all over the place. We stop normally in July and assume if we don't get the remaining eggs by September they are done. Granted we started our pairing in November and had a girl we thought wasn't going to go last year lay a clutch one day after being paired up once this season. It was a left over clutch from last year naturally, but it just goes to say don't give up on them.