I am on aygestin (norethindrone) and metformin for pcos. my doc is hoping that it starts a period. would light to moderate spotting count as a period?

Probably not: If you were given aygestin (norethindrone) to make a period come down after a long time if no period then you should expect a real 3-4 day period.

Generally NOT: Without an actual examination, I cannot give specific medical advice on your particular health but spottiing is common in PCOS mostly as a sign of hormonal derangement (abnormal irregular menses).