Good day, I'm 20 years old and my last period began on May 10th and end on May 16. I normally see my period every 43 days on average so I was expecting my period on June 23rd however it hasn't come as yet and a new month have started, I also have belly cramps which I normally have each month when its close to my period. I took two home pregnancy test and they were negative. What could be wrong? Any suggestions will be helpful :)