The experiences here vary. I was disappointed in my first semester because my classes were not nearly as intense as I was expecting them to be - and I was already taking two upper-level classes that everyone advised me not to take because I would be overwhelmed. Most of my friends agree that the typical Haverford class is more challenging than the average class at Bryn Mawr, and Haverford students adjust and deal with the workload just fine
You sound very well-prepared for Bryn Mawr. I don't think you have anything to worry about.