ok so i bought what i thought was a great thermometer. it was made for reptile tanks so i figured it would do good with higher temp readings. the first time i used it was to hatch ducks and they hatched 3 days late. i figured it was just the fact that i was using my home made incubator for the first time and had to adjust things durring the hatch well this is the second time and eggs are due today however they havent started. when i candle i can see them moving around in the egg but no internal pip yet. could my thermometer be off and what is a good way to test that? thank you!