Any advice??

Hey ladies, so I'm 28 and my husband and I are trying for our first. I had an iud for about a year and a half and it was taken out early January. At first my cycles were fairly normal but now they get longer and longer. I am on day 42 and 3 pregnancy tests negative. I've been checked for PCOS and that was negative. I don't really know what to do. Any thoughts?