Without reconstruction or sentinal node biopsy hopefully you will be fully recovered in 3 to 4 weeks. 6 at the most. The drains are in for around a week (for most people, but this varies a lot) the scar line is healed in 10 days when stiches come out so a couple of days for holes to close over. You'll have some stretching exercises to do to regain strength but as they won't be cutting muscle or tunnelling to nodes you should get movement back quite quickly. They should give you instructions how long to not push / pull or carry things so not to put strain on the scar but I would think 4 to 6 weeks at the most. I'm sure other ladies here will have more information. These 2 links have some quite good information. A little more than just the explanation of surgery.
http://www.nhs.uk/Conditions/Mastectomy/Pages/Recovery.aspxhttp://www.breastcancer.org/treatment/surgery/prophylactic_mastAnd a great link for exercises in case you are not given information.
https://www.mskcc.org/cancer-care/patient-education/exercises-after-breast-surgeryYou should still be linked with a breast care nurse. Please ask about this also. Best of luck. Kath x