Peppers germinate for me in about 4-5 days sitting on the heating pads. They probably makes the soil a bit above 80 degrees.
If your bell peppers haven't germinated in two weeks, I would give up on them and start over.
Crops - Peppers
32ÂºF - 0%, 41ÂºF - 0%, 50ÂºF -1%, 59ÂºF- 70 (25) , 68ÂºF-96(13), 77ÂºF - 98(8), 86ÂºF -95(8), 95ÂºF - 70(9), 104ÂºF - 0%
this is his report on effect of soil temp on germination rate and time. So at the three lowest temperatures 0 or 1 % of the pepper seeds germinated. At 59 degF 70% germinated, but it took them 25 days. At 68 deg F, 96% germinated in an average of 13 days. At 77 degF , almost all of them 98% germinated, at an average of 8 days.
The trouble is if the seeds are taking 13 days to germinate, that is 13 days the conditions have to be kept perfect. If the seeds dry out, they will die. If the seeds stay too moist, they will rot out and die. So the longer it takes to germinate them, the less success you are likely to have. I suspect that his report is with perfectly consistent conditions in a lab, but we can't all do that.
Honestly, I wouldn't even try germinating peppers without my heat mats. They aren't very expensive. You can get the ones like this, sized for one 10x20 tray, for about $20