Blood Pressure Questions

New BT user here. I had a high blood pressure reading today and am a bit freaked out. HIGH high. Here's some background:

--my BP has always been around 120/65.
--I have been pretty fit most of my life, except for a 10 year period of college and post-college where I got really fat.
--I recently lost over 40lb, but am still about 20-30 pounds overweight, working on getting to my goal. I work out between 6-10 hours a week. Eat fairly healthy. Oh, and I'm a 28yo female.

--I had strep-throat last week and my BP then was 135/70-something. I was told it was probably because I was sick.
--This morning I had an OBGYN appt and it was 169/?? (don't remember after hearing 169). They took it again at the end of the appt and the top number was 172.

--Being sufficiently freaked out, I bought a home monitor on my way home from work. Tonight it was 160/86. Still REALLY high! I am supposed to monitor it over the next few days and then call her with the numbers. I'll cut back on salt, caffiene, and my sweet sweet ibuprofen in the mean time.

I am wondering if there is something besides hypertension and other medical issues that could cause this spike. Like, I did a half marathon on Sunday and am recovering? Or that I have been taking a lot of ibuprofen (a lot meaning 400-600mg 4-5x/day, yeah, I know that's not great, but I'm sore)? I had a couple cups of coffee this morning, but that's nothing unusual. No dietary changes, other than for the better.

I'm just shocked because when I was way overweight and sedentary, my BP was fine. Now that I'm doing everything right, it's not. Disappointing.