Two days ago I started recording my dreams, and doing reality checks every day (at least 20 a day).

I found two good ways to do reality checks:

Close your mouth and hold your nose, and if you can still breathe, you will be dreaming. Try really hard to breathe. Most likely in a dream you will actually breathe while holding your nose. I once had a dream where I could breathe underwater (it wasn't a lucid dream either).

Another reality check: peeing. If your bladder is kind of full, go to the bathroom and empty your bladder. If you feel relief, you are not dreaming. (hopefully you won't pee in bed).

These aren't guaranteed to work though.