Hi I Wander If You Could Help I Have Been

Hi
I wander if you could help I have been doing Slimming World plan for 2 weeks tomorrow , My first week I only lost 1lb , and stuck to plan .. This week I am due to be weighed tomorrow and I am in a lot of pain in tummy really swollen tummy , feeling worse than when I started .. I have a feeling I will not lose this week with all this swelling and constipation .. Just wandering if I should keep it up
Thank you