I would say that it depends on how long you have been trying and if you have insurance. If you have been trying for 8+ months and have isnurance coverage, go with the Clomid. If you have been trying for less than 8 months or don't have insurance, I would go with the fertilaid for now.
With your cycle being as irregular as it is, I think it's best to go with Clomid as soon as you can. More than likely you will end up using Clomid so why wait if you don't need to?
Just a thought.