starting Stims

Nicole • 34 years old. Married for 8 years. 1 angel baby. Ben arrived 9/18/17 (5 weeks early)
I just finished BC on Tuesday night. I am supposed to start my stims on Saturday. I woke up this morning with some bleeding, should I notify my doctor? Am I supposed to start stims on day 1 of cycle? Do I wait since it is not a full flow as of currrently?