Heart rate in 80s-90s tonight, it's scaring me

Hi everyone, I am a little bit freaked out. I have not had many issues with heart anxiety lately, but tonight I am freaked out. My resting heart rate is normally in the 60s and low 70s, but for some reason tonight I have been in the 80s and 90s even just sitting down. It is scaring me (which I'm sure probably isn't helping any to bring it down). Is this a normal fluctuation? I worked out earlier with a heart rate in the 130s like usual. I have been hot and work today was a bit more stressful than normal, if that can have any effect.

I have had an EKG done in the past month and it was normal. Any advice is appreciated - thank you. 

80s-90s is still in the normal range for a resting heart rate. Mine will sometimes climb to 120s out of no where and I’ve also had EKGs, and echo, blood work, and cardiologist says I’m fine!

Your fine, when I m anxious my heart rate is 90 -100 when I’m relaxed not anxious it’s 60-70, it’s not going to do you any harm more than likely your completely focused on your heart rate which is increasing it. You probably not aware that your doing it to yourself