
Welcome to the forum. For some women, it takes a while to get 'regular' and some don't without help from a regimen of hormones prescribed by an OB/GYN doctor, so the best bet is to see your doctor as soon as possible.
I've included a document explaining a little more about menstruations and hope it does you a little good and reassures you.
Good luck, and please keep us posted.
Just click twice on the document and it will open.