Is my rabbit pregnant?

hi, my male rabbit escaped the other day to be with my female and they were together for about 20 minutes and i saw them mate about twice but i could not get to them as the were in the garage under the car lol , they have and do sniff each other about everyday through the hutch. i am quite excite at the thought of baby bunnies :D but do you think it is a strong possibility and what should i prepare?