My RE says to "take it easy" after the transfer and to resume normal activity (within reason, no exercise, etc) the day after. Bed rest has not been shown to increase pregnancy rate, but many REs recommend it anyway. My RE calls also for pelvic rest (no sex, orgasms, etc) until farther notice. When I had my low betas, pelvic rest continued until beta reached 0.
You have to do whatever you think you need to, so that in the case that it fails, you won't be kicking yourself thinking 'I wish I had done..."