Hey
My hubby used to work on oil rig. But he changed his position. Now he only goes once in a while. If he had not changed his position I would have requested he come home when he's working at a rig that's less than 3 hrs away once I confirm that I'll ovulate with a positive opk.
How long are your cycles? If they are average and you ovulate at the same time each month, that could be causing you to miss your fertile time. I suggest you take temps for the next few months and use opk (but most important is charting your temp)
If he's not that far away from home, maybe he can drive home when you get a positive ovulation test.