Cramps

I have been having cramps on/off since before I even found out (I didn’t even think I was going to be pregnant as it felt like my period was coming!) I’ll be 6 weeks on Thursday and most days I have cramps, today they have not gone and I have had them all day. All in my lower belly and back and now it’s shifted to the left side lower belly and pain just above my rib! I’m so worried but I haven’t even got a midwife yet (I’m in the UK, I have my first appointment over the phone on Thursday) any ideas what it could be? I have had no bleeding