Congratullations!
At 9 weeks, you are probably totally fine. The body has a way to protect our little ones while they are super small.
I tend to stay away from anything that will heat me up, but I'm so darned hot all of time! I also stay away from anything electric as much as possible due to the EMFs. I may sound off the deep end, but I would rather error on the side of caution for everything. How many times has science gone back on what they orignally thought was safe? I rarely use a cell phone, I never use a heating pad, but maybe an old school hot water bottle and I don't have any ultrasounds....and I'm pregnant with #4.
Don't stress. 2 days should do NOTHING and for only 30 minutes? If I have pain, I use a really good CalMag supplement, as it's a natural painkiller and muscle relaxant.