Laying on a Heat pad helps me
You can also look into Chiropractic care!! It sounds like SI pain. I work at a chiropractors and am 15 weeks myself and the adjustments help so much!!! The doctors I work for treat and adjust specifically with a low force technique called the activator method!! Definitely check it out! :-)
You're not supposed to use heating pads while preggo. Talk to your doc.
You should not use heat with SI pain. It can inflame the muscle and tissue surrounding the nerve. I am 14w and have been going to the chiropractor for two weeks for it. Use ice for 20 min then wait 2 hours and repeat. Try not to sit on soft surfaces. You can try to stretch it out by lying on the floor and brining your knee up to your chest and holding for 10 seconds. Good luck to you, I know it's hard to live with.