Trying to conceive

I removed my iud 8/2/14 and had normal 35 day cycles for 4 months including august. December I was 44 days late, missed a cycle in January but I had a positive ovulation test jan 10,2015 and didn't receive my period til February 25, starting to get fraustrated, I have had 2 prior pregnancy and never had an issues getting pregnant. Could my iud have effected things also I have been using clear blue digital ovulation kits. So I have been trying all along just no luck yet. And now I have no idea when I will ovulate since my cycles are no longer normal. Any input would be great