I wouldnt say that its not normal.. My FS told me it depends on certain things.. Like I am been monitored because there are twins on either side of the family, and the FS would prefer me to have one healthy baby instead of multiples. And she also told me that they are monitoring to see if I am on the right doseage, the right days to take it, to see if any follies are there or weather or not my PCOS is preventing it...
You could always ring and ask your FS if you are worried...
HTH