3 weeks 5 days and strong symptoms…

3 days ago (9DPO) I got my first positive test with FRER. I have taken four different brands of tests and I have taken at least one every day and the lines have been getting noticeably darker when I take two or three of the same test on different days (yes I am crazy). I can’t believe how early it is and how noticeably different my body is. One of my smaller bras is getting uncomfortably tight, I am feeling sick, so tired, and I definitely have pregnancy brain. But the thing that is surprising me the most is my blood and heart has immediately reacted. I get periods of frequent heart palpitations that last for several hours and my heart feels like it’s pounding. My normal resting heart rate is around 70-75 and right now it’s 95-100. I will be laying on the couch because I’m really tired or not feeling well and I suddenly realize my heart is pumping like I went for a short run. I get out of breath carrying laundry to the bedroom or putting new sheets on the bed. I know this is considered relatively normal in pregnancy because blood volume increases, but has anyone else experienced this even before the date their period is expected?