2 Wtf's

I was driving home on the highway doing a constant speed and when i went to just pass slowely to the point where the tranny didn't shift down it felt like i had hit a bump but i didn't, its hard to explain, all i know is that it felt like i hit one but i know i didn't. The second prob is i was driving home on the highway doing a constant speed with the cruise on and for some reason i felt a bump again same as b4 but my rpms went from 1700 to 2300 back down to 1700 then to 2300 and back to 1700 and then it was fine, this all happened on a straight stretch of road, any ideas?