Levemir issue!

I would guess you at least got some units. I wouldn't inject again in case you hypo. Keep testing and adjust bolus as required. Good luck.

I don't think you can tell whether any went in. I would try another shot into the air and see if anything comes out? I wouldn't do another injection today but resume again in 2 4hours. I guess it could have been air, but there should be very little in the cartridge

I was always told that if something like that happens (or if you can't remember if you injected or not), it's always best to assume insulin went in and then be too high but able to test through the night, then give another dose and being too hypo to even test, especially with the risk of a night hypo. My advice would be to test every couple of hours through the night and correct with small doses of short acting insulin if need be.

There shouldn't be any air in the cartridge. It might be that your pen is faulty if it feels like there is no resistance when giving a dose. If it happens again I would ask for a replacement from your HCP.