Horrendous diarrhoea

Hi mums, 30 weeks. I’ve had the worst tummy cramps for about two days now. Truthfully I thought it was braxton hicks. well this morning the diarrhoea started. It hasn’t stopped, it’s awful 🥺🥺 I can’t eat because it’s making me feel sick. Just managed to stomach some toast. But at what point should I be worried or shouldn’t I? Xx