Hi
I haven't gotten that related to a bfp- but had it later in preg with my DS- heartrate was 192...not fun
I take asthma medicine tho and get it maybe 1-2 times a yr- not sure if related.
The only other time it seems to happen is if I haven't slept for a while... ot a real prob other than being draining after a while - like you have been on a long run, but I'd mention it to your doc if it happens more often/longer or if it's over 150s for a while- we actual treat that at the hosp here if it stays up a while. Oh yea, sorry caffeine sensitivity will do it as well- try to stay hydrated - GL to you!!