I'm currently 26 weeks pregnant. My stomach gets rock hard for 40 seconds every 15-30 minutes. I'm having this hardening since i was 16 weeks but it wasn't so frequent. My doctor has put me on duvadilan 10mg 3 times a day but I don't think it's helping. I'm also on proluton 250mg injections weekly, and susten SR 300mg nightly. I'm on bed rest lying on my left side mostly. Is this a sign of preterm labour? Is there some way to stop this? I'm really scared and I don't wanna lose my baby again. I have a cerclage and pessary places at 13 weeks due to history of miscarriage at 17 weeks last pregnancy due to incompetent cervix. Please help.