Aw, hugs to you Blue, and prayers that everything turns out OK.

Speaking only from my breast biopsy this summer, unfortunately I think you'll be in too much pain to ride for the first 2-3 days anyhow, no matter what the doctors tell you (I have a pretty high pain threshold).

After that the bleeding shouldn't be very heavy (although if it is, I'd take it as an indication that the movement was preventing the incision site from healing, and back off). If it was me I'd just wear black shorts. Who cares if your chamois gets stained? (Assuming you have a black saddle of course.)

Keep us up to date (((((Bluetree)))))