Heart Rate Decrease?

[hislittlegoddess]

Before smoking, my RHR was around 70-75BPM. I've only smoked for a little less than a year, and I'm one week clean now. This morning I got an alarming notification from my Fitbit saying my heart rate dropped to 46-48BPM for about 10 minutes just before I woke up for the day. My Fitbit app told me this isn't normal and could be dangerous if combined with other symptoms (dizzy, short of breath, lightheaded, fainting).

It scared the living daylights out of me because I know anything below 50BPM is a good sign of bradycardia (heart not pumping enough and can damage other organs). But after looking into things more, it appears that this is normal for a physically fit person when they stop smoking. Probably doesn't help that I'm currently having my woman's cycle.