Not pregnant?


So last month my period came earlier and lasted longer.I ovulate late most of the times.My period is not extremely stable but it is not unstable either.I get my period once a month,expect February because it is shorter and my my cycle lenth is 34-36.My period finished on the 31st last month and this month my period still hasn't appeared.I tried a pregnancy test today.I was so disappointed.I trust clearblue very much but I dont understand what's wrong.

P.s I dont have pcos