Hi
most couples will fall pregnant within 12 months of actively trying to conceive soometimes for no reason at all it may take a little longer than just one or two trys where I live they wont test you for fertility unless you've been trying for a year. You can see if your ovulating first you can buy kits from a chemist and when you are go for it as much as possible in that time if your worried that you may not be able to fall pregnant then possibly speak to your doc. Maybe wait a few more weeks then take another test.
I hope that helps you. Take care