Changes in nipple sensitivity...nervous!

Tina
Hi ladies, I have had two 6wk MCs and now I am pregnant at 9 weeks. Saw ultrasound last week and heartbeat was 153. Things seem to be on track more or less. 
I woke up this morning and my nipples are not as sensitive as yesterday. Should I be nervous? Or does their sensitivity fluctuate with normal pregnancies and I'm being hyper sensitive? 
Thank you!!