I have this exact same thing. Its actually what started my whole worry over my health when a Dr. did a 24/hr holter on me and found my heart rate getting in the 30's. But to this day I still have a very low heart rate, especially when waking 45-55 with also the ecotopic beats that feel like palpitations. Dr. told me that the cause is what they call PVC's, so a premature beat so its actually not skipping, but waiting to reset for the next beat since you had two beats in a row. With the low heart rate, the only time this can be worrisome is if you are symptomatic like you feel like your going to pass out,dizzy, or extremely short of breath. Bare mind though these can also occur when you have anxiety because of this which usually is why its good to just get a doc to check it out. But yeah I get low heart rate resting or even standing. Also, heart rate will vary so much so alot depends on what you just did or whats happening with you when you check it. For eg if you had eaten prior and then had checked it it could have been up or if you didnt get a good night sleep, it will cause you sometimes to have a higher than normal heart rate which you probably are using as your base. Dr. also told me if your heart responds to exertion, meaning goes up when you exert yourself then usually thats a sign you dont have a worrisome bradycardia.