Concerned about late appt..

Chealsy • 26. Babygirl born 4/15/16.
So I just recently found out I was pregnant. When I called my doctor to schedule an appointment they said that they schedule 8 weeks out from the first day of your last period. However, I'm not sure that I honestly know if the period I had at the beginning of August was a period, it might have been implantation bleeding. I stopped birth control July 12, last known period while on birth control was June 30. I bled for 4 days starting August 6. So I gave them that as a date. Now my first appt isn't until October 2. I'm worried... Sorry for it being so long. Should I be concerned?