Blood on tissue and period cramps advice please!

Emilly
I am 35 weeks + 3 days. 
I went to the toilet and there was red streaks of blood on the tissue paper. I haven't been the toilet again so haven't seen anymore blood. But I am getting back ache and period pains. 
I have done a kick count and he moved over 10 times in an hour. 
I had an ultrasound yesterday because they thought the baby was measuring too small. Everything went well turns out it looks like I'm just having a small baby. 
My plans are to ride it out and if I don't see any more blood call the midwife and let them know what happened. But if I see mall call and let them know sooner. 
I just wanted to know if anyone else had experienced this.