dVH/RALH Nausea plus one other question

Hi sisters!
I will be two weeks out (on Thursday) from my Total Da Vinci Hysterectomy with BSO. I am feeling pretty good, able to walk a lot, not in too much pain etc.... My problem is nausea. Starting 3 days after surgery, I started getting nauseous (and that first night, I did vomit a lot). Since then I sporadically get so very nauseous. The first time we related it to the pain medicine but I'm not on any pain medications anymore. What could be the cause of this, I feel so sick to my stomach?!
Also, I am on the Climara Patch and everything is great until about 6 days in and I start getting the hot flashes horribly. I don't change the patch until day 7, am I doing something wrong or is that how it just is?
Thanks for you help!

Starting estrogen therapy can make some people nauseaous. Also the patch can "run out" early on some people. I am taking oral estradiol and having my own set of problems. I personally get nauseous when my estrogen is too low.

I guess that could very well be the cause. It's just miserable!