Clomid ... late period .. help

Cecily
So I started taking clomid on Dec 29th for 5 days 50mg... it is now day 28 took a hpt, and it was negative. My bbt drop a little today but my cervix is still really high... is this normal can clomid throw off your period... I'm normally 27 days... idk what to do.. I'm losing hope more and more everyday....