Period but still a positive test

Hi ladies,
I'll start from the beginning.
I've been taking the pill continuously for 4 years, with occasional breaks every 3 months to induce a withdrawal bleed.
Last month I stopped, and got my period right after (5 days).
Three weeks later, around January 1st, I should have gotten my period again, but it was late... I was 7 days late, so I thought I'd better take a test.
It was negative and I put it away quickly.
That evening I had a weird feeling and decided to look at the test again... Suddenly there was a faint line.
When I went to look it up, I read quickly that it could be an evaporation line, so I planned to get a digital test from a friend the next day.
I woke up in the morning and yes, I was bleeding.
So my hopes were dashed quickly.
I bled for 5 days, then it stopped.
After 7 days, I noticed a little bit of blood again.
I thought, okay, it'll probably just be irregular.
Sometimes it's heavy, sometimes it stops.
Last night I thought it had been over for good, so I thought I didn't need protection anymore for the night.
But this morning my pants were full again. Now I'm on day 4; I woke up with nausea and then felt pressure in my lower left abdomen that radiated downwards.
I thought it was probably my first real period, so I took a paracetamol and went for a walk (which wasn't a huge success); the pressure persisted.
A friend told me I should really take a test.
And yes, the test was clearly positive.
I immediately called the midwife and explained everything.
She also found it a bit strange, but unfortunately, I can only have an ultrasound in 3 days. She said I should call and go to the hospital if the pain got worse.
Right now I have a clean pad again, so it looks like it's stopping again.
But getting up and lying down is very sensitive.
I'm scared.
I also assume it might be a miscarriage.
But these days are going to feel long.
Has anyone experienced something similar?
I had a miscarriage 6 years ago, but with much more pain, real stabbing and cramps. Now I only have pressure and everything feels tense when I lie down stretched out.