it would be highly unlikely that the symptoms are due to
pregnancy, because, as you suspected, it is too soon in the cycle to be having pregnancy symptoms. occasionally some women might have similar symptoms with ovulation, and you are around the time of ovulation, which may be an explanation. however, if that were the case, you would most likely feel these symptoms every cycle at this time, and it sounds like these symptoms are new to you.
I can tell you though that
hormonal symptoms sometimes come up due to random hormonal fluctuations, and we often don't really know or ubderstamd why they are happening. if they resolve in a few days and don't recur, it is generally not worth worrying about. however, if in your case these symptoms don't resolve in a few days, you should see your doctor to check your levels of
thyroid hormone, prolactin? and others. I hope this helps, please let me know if you have any more questions.