I was like this at 29 weeks, just a normal night had my tea just relaxing on the chair but all day on and off I'd had weird feelings like period cramps. Then during the evening they gradually got worse but nothing I couldn't handle, then around midnight I had to go to the delivery suite I was checked over and I had started dilation! I was 3cm dilated and they had to stop me from labouring. I was given steroid injections incase baby was born early and given a drug which stops contractions and labour. I was kept in hospital for a week and checked constantly! I had to take early maternity leave as recommended by my consultant as she wanted me to have as much bed rest as possible in case of an early delivery. But here I am at 37 weeks and still pregnant this baby got back comfy again haha.
But to be on the safe side I'd go to your local delivery suite or get in touch with your midwife for a second opinion xx