Milk taste in mouth

Hi ladies, I’m 4dpo(or more if ovulated earlier) I’ve been having cramps in my lower back and lower stomach and pains in my breasts. Ive been really calm these past few weeks ttc and I got a hot flush yesterday and after that I felt really sick and today I feel really down. I’ve suddenly just got a taste of milk in my mouth like a sweet taste. Anyone know what this could be?