I was diagnosed about 15 months ago, but I can say that i have had what you were experiencing for as long as I can remember. I have had racing heart beats, missed beats, weird groupings of what seems like 2-4 beats really fast, then a gap and then back to normal.. I have had the works lol
Last December i saw my doctor and thought 'Maybe this is from my newly diagnosed diabetes?' and i was put on a heart rate monitor for 3 days full, and they also did a bunch of other tests.. I got back the results and was told everything was totally normal.
The problem isn't what my heart was doing, but that i was sensitive enough to notice is what i was told.
When you look up these issues you will find they are VERY common, usually benign, and always kinda frightening lol
They aren't said to be an issue until a person experiences something like 20,000+ missed/racing beats each day...
What you are experiencing is more then likely caused by anxiety (as was mine), they get more prominent with mild stress, or lack or sleep, or poor diet, and then people start to notice them, and that makes them more stressed out and then they get worse, and that circle continues for a while.
The key is to take your vitamins, sleep lots, and be healthy. When they happen and you notice something strange just take a breath- laugh it off and move on with life or sleep lol
If its really bad you can see a doctor but without a long serious of tests, you will likely not see a result, but you may get drugs out of it lol
If it gets very intense then certainly see someone, but if its just a quick wake up and then back to bed it may just be stress.