Trying to get pregnant!

We are trying to get pregnant! We have been for about 5 months now. I have been pregnant once before but have no children, the first time it seemed to easy. I have tried tracking basal temp and everything possible but got frustrated and decided i was stressing too much, that it was about timing. We decided to just let it happen but now my periods are not as predictable, are more intense, and with every negative test I'm getting more discouraged. :( Anyone who has been through this or anyone with advice?