Cycle tracking as birth control

Does anyone here successfully track their menstrual cycle as part of or their primary birth control method? I’m curious about how effective people have found it.

Disclaimers: I practice safe sex using a condom/pull out method and have not had any issues so far. Hormonal birth control does not work for me because of interactions with other medication I have to take. My partner and I are monogamous and have been tested recently.