As of December I had my iud removed an in Jan I had a 3 day period which is normal for me an again in January and again I had a 3 day period the 10th of Feb which by using a ovulation app to get pregnant has figured out that I have a 33 day cycle and most have a 28 day cycle nehow I followed the app to a T and it said I could be fertile between the 24th to the 29th so my husband an I had sex on the 24th and 26th an again the 4th of march now I'm 8 days going on 9 days late today , my period was due march 14th and it's the.22nd and I've taken 4 pregnancy tests that have all been negative an I feel pregnant , does anyone know if I might be an maybe my hormones just aren't high.enough for the over the counter pregnancy tests.