Clear Blue Digital Pregnancy Tests

Hi Ladies,
Please help a friend. I am 14-15 days DPO not sure if i ovulated the 1st or 2nd of June. This is my second month on Clomid so my period should be regular. First month I took Clomid started my cycle day 27th. Today is cycle day 30 and no AF yet. I took a clear blue digital this morning and it said NOT PREGNANT. I did some read online that cler blue digitals are not accurate the cheaper tests are better. Has anyone been in my shoe? Please give some advice on what to do? Thanks a lot.