I weigh 175lb and am 5'3, should I lose weight before my BBL in February?

I think that you should be at or close to your baseline weight before undergoing BBL surgery. This means that you should not gain or lose weight specifically in preparation for the surgery. Being at your baseline weight will allow the surgeon to get a better result and make your result more long-lasting. I perform several BBL per week and questions about weight are the most common questions they ask. Make sure your surgeon is a board certified plastic surgeon who does many of these per week. Good luck.

              In general weight should be stable prior to the procedure, because weight tends to return to preoperative manipulation.  I usually suction 5 liters of fat and transfer 1200 to 1500 ml per buttock, but I alter this to meet patient goals.  I would have to see pictures to make any further recommendations to assess skin laxity and areas of lipodystrophy and formulate a plan for you.  Good luck.

Hello dear!
Thanks for the question and provided information as well.
Your BMI is within the recommended range, but unfortunately, without pictures, it is very difficult to give you a proper answer. 
In general, you need to be physically healthy and at a stable weight, have realistic expectations, be a non-smoker and your BMI needs to be 30 or less.
l recommend you to make an appointment with a board certified plastic surgeon to talk about your goals and anything you need to know.
Good luck :)

Everyone looks better after weight loss.  Losing weight prior to surgery may enhance your overall results, by making your waist even smaller.  You will likely still have enough fat left to transfer.  Please discuss this with your plastic surgeon.