Uterus pain at 4 weeks


I am 4weeks and 6 days today. I’ve been noticing for the past few days that in the mornings if I stretch, my uterus feels like it will cramp up so I quickly stop stretching. It also feels sore but as I get up and move around, the sore feeling quickly goes away. I had some cramps yesterday and I know by now the baby is very well implanted and growing so I’m just worried. Has anyone else experienced this? I have my first doctors appointment on February 1st.