May be past tense already, Mike, if they've beentogether! Doesn't take much for a doe to getpregnant. We are virtually talking no foreplay,here. However, not assumingthe worst case scenariothat she isalready pregnant, there might be a number ofreasons for you to prevent mating.
First, there are literally thousands of rabbits lanquishing in rescuefacilities awaiting adoption, or more likely, extinction.Unless, you already have prospective homes for any potential bunnies,you would be adding to an already horrendous problem.
Secondly, not much of a market for cross breeds if you havethe slightest delusion that you might make a profit from breedingbunnies. Although, you might find an irreputable pet store totake some, or all, they are about maximizing profits and NOT making youwealthy. Pet store bunnies often are misrepresented topotential owners, ill cared for, and many prove to be expensive medicalliabilities in the long run.
Thirdly, the couple will reproduce about monthly unless you provideseparate facilities to keep them apart, which means duplicating allyour efforts and expenses for feed, caging, care, etc. If shehas a litter(s), you will have to provide housing and feed for thelittles ones until you can find outlets for them to go to.
If you do want to keep both together, it is high recommended that youneuter both animals in the interests of good health, longevity of life,and reduction in undesirable sexually induced behaviors like biting,aggressiveness in general, urine spraying(directional and highlyaccurate, I might add), mounting, circling, and others. Theyand you will lead much happier lives together if the buns areneutered. Ask any experienced multiple pet rabbit owner.
Best bet, Mike, for all concerned, is not to let them reproduce.
Buck