If its been compromised the test wont be posistive. HCG is secreted right after conception in pregnant women its a safety mechanism placed there from times early on when food was not as readily available and days would pass without eating which would be catastrophic for a developing fetus. The HCG works on stored fat to give a constant release of energy for developing fetuses.
Having said all that if your HCG has crashed then Pharm grade or not the test will not show positive. Also I travel quite a bit for work and I often had preloaded pins with HCG and had in my carry on without refrigeration and it was fine. Even for a full 10 hours while on a flight overseas. My guess is that its OK. There is some wiggle room there a few days you might have a problem but overnight should be fine. It's not like you cooked it. It was body temp the same temp it naturally is. The refrigeration part is primarily there to not have it in a temp zone that is not conducive to bacteria growth.