Has any of you found maternity leggings that you're happy with? I have bought a few pairs from very cheap New Look ones to a ridiculously expensive Seraphine pair and they all seem to ride down as I walk 
I'm only 16 weeks so my bump is still pretty small - perhaps it will get better when I actually have a bigger bump to keep them up?! Also I have straight/slim hips which I guess doesn't help.
I prefer over the bump but open to suggestions.
Thanks very much!