Breakthrough bleeding considered period?

[SheeBopp]

Okay. I have called and tried to explain to my OBGYN and only got to speak to the medical assistant whom wasn't any help at all. I had gotten my period April 26th-28th. On Monday, April 29th, I went to the OBGYN office to start my birth control. I was given loesterin 24 Fe which I began taking that same day. I didn't take it the next day (Tuesday) because my son had taken out my wallet which had my pill pack in it and had to take it while I was at school. I took 2 pills the next day (Wednesday) to make up for it. Continued to take it thurs-Monday. That Monday I had what I think was breakthrough bleeding which was EXTREMELY heavy. Called my OB & staff said that he wanted me to stop and if bleeding continued, to come in the next day. Bleeding stopped within 3 hours. I have not taken any pills since then and was wondering when I should expect my period to come. My period is usually 30 days & never a day late. So my question is: Do I count 30 days from my first day of my last period OR from the 3 hour bleeding I had on Monday May 6th? I have had unprotected sex from day one and went to know when to expect my period. I wont see my OB till This coming wednesday. Im just looking for some insight. Thanks in advance!