TMI... I'm so confused.. sorry for me rambling my thoughts are everywhere

So my husband and I have been ttc 11 months I finally got the bfp on 11/3. I know my lmp was 10/7 flo said I ovulated on 10/20 so we did the deed and got pregnant well I went to the doctor as she I was 4 weeks and so I went to my ultrasound yesterday (would've been 9w 5d) and they said that I'm actually around 5 weeks.. they did the transvaginal ultrasound.. well 2 days before I started light spotting brown and then it stopped.. skip to ultrasound after that I started having mild cramps and again brown spotting which I know is normal after a exam but last night I wiped after I went to pee and it's this brown and mucus thing and now today it's brown & pink blood.. I'm terrified I'm having a miscarriage.. this is my 4th child my last pregnancy was high since I've had 5 pregnancies and a miscarriage....

My questions are,

1) Has anyone had such a dramatic change on how far along you are.. 4 weeks different

2) is this normal could it possibly be a miscarriage