Period pains increased discharge and feel sick 35 weeks pregnant

Hi could anybody tell me their experiences of this

My baby had a growth scan 2 weeks ago and she had dropped to lowest percentile I'm now 35 weeks pregnant today and for the last couple of days I've had an increase in discharge but since yesterday afternoon I've had constant pain in my back that feels like I'm going to come on my period I also feel like I need to poo but I actually don't need to (sorry for the tmi) also been getting headaches and feel very sick. Should I call my midwife and tell her what I'm experiencing or is it normal.. Just looking for some advice also I'm getting sharp pains in my vagina that feels like lightening crotch thank you