High pulse a week postpartum

I’m wondering if any of you are experiencing this? When I’m laying all is fine but when I stand my heart rate spikes and it’s usually 110-135. Drinking water seems to help. I did call and talked to a nurse who told me to let them know if I experienced chest pains or high blood pressure with it.. but I’m wondering if anyone else is having this same issue? Is my body just recovering? Is it from the extra blood in my body?