I've done a little research on Braxton-Hicks contractions, but is it possible to get them at 17wks?

You can, but most women don't feel them that early. Your uterus contracts much of your pregnancy but they aren't often felt until closer to the end. Sometimes, if you aren't taking in enough fluids, you may feel more contractions... this is why one of the first things suggested to women who are feeling a good number of contractions is to get plenty to drink as it may help the contractions subside.

It is very possible if this is not your first pregnancy. With each pregnancy Braxton-Hicks contractions show up earlier and earlier.