welcome to dream views,

what you experienced was your mind testing to see if you were awake, if you responded, it knew that your body was not asleep, so you will awaken completely. You were probably closer to getting to the dream than many people here, so next time that happens dont get up.

Your heart rate is also supposed to go up when you are about to enter a dream, so just dont be afraid of Sp, just go thought it.

you may also want to check out the tutorials section and the quick start tutorial for extra help.