I'm a 21 year old female.. and just doing a 20-25 min power walk my heart rate jumped up to 200-201

I'm a 21 year old female.. I'm 129 lbs and 5'5. I havent worked out in a few months.. but I recently started a new gym I got on the treadmill for maybe 20 mins and when I looked at my heart rate.. it said 180.. I thought wow.. that seems kinda high.. then I got on the eliptical.. for about 5 mins an dit got to 200-201. ALso in the past few months I've woken in the middle of night with a slight shortness of breath and a cough.. i started taking allergy pills and the cough as gradually went away.. I feel no symptoms of anything .. Other then I feel stressed and kinda tired sometimes..Is there somehting wrong with me?.. Should I be worried?

[CCF HeartMD3]

Tristan32,

The maximum predicted heart rate is determined by the following equation: 220-age. When you use this formula for you age, your heart rate after exercising is within that is typically considered to be a normal range.