Hello, I am 38 + 5 days pregnant and have

Patient: Hello, I am 38 + 5 days pregnant and have been suffering with constipation for the past few days. Really bad cramps when needing the loo and then not being able to go at all or just a small amount. I have also noticed that my stool is now black coloured.What may be causing this?What can I do to help?Should I contact my doctor?Thank you

Doctor: