Is it normal to have some spotting after 7 days of stim medication for ivf?

No. That does not usually happen. Once and a while it an signify a polyp in the uterus. It is possible that if you did not respond well the uterine lining did not grow and was thin. Or it can happen when your hormones go up and then drop and the lining of the uterus sheds a bit. Sometimes it can occur for no reason. But it is not common.