High Resting Pulse Rate

Hello,
I am 27 years old, 5'2", 175 lbs. I am recently diagnosed with HBP. My doctor originally put me on Aldomet because I'm trying to get pregnant and after a week and a half I had elevated liver enzymes and fever so I went off that drug. I have now been on Hydrochlorothiazide for about a week and it is controlling my BP very well. However, I have noticed that my resting pulse has been steadily getting higher since I have been testing my BP at home with a monitor cuff. Going back through all my readings I am usually around 75-85 bpm but since I got on the diuretic I am never lower than 90 and am frequently 100-110. This morning right after I woke up I had a resting pulse of 106. Is this because I have less water in my body due to the diuretic? How serious is this? I have read many articles that say your resting pulse should be between 60-100 and usually 60-80 bpm. I realize that I am overweight but have already lost 20 lbs since the Aldomet issue. I have been working out daily although I'm not in good shape yet. When I work out my heart rate is anywhere between 140-160 bpm.