One week late

Jamie • Mommy to a 3 year old little boy. 🌈 rainbow baby coming April 2019 ♥️

I am one week late for my period and it doesn’t even feel like it’s coming! (CD 37) I took a pregnancy test on Wednesday and it was a big fat negative. I keep having muscle spasms in my lower abdomen which is really weird and I have a few cramps but they do not feel like menstrual cramps. I don’t have any pregnancy symptoms so I’m not really sure what’s going on. Anyone ever experience this? Or have any advice? TIA!