TTC - have I had a MC???

So I’m 35 and my partner and I are TTC (my first baby) my partner had 1 child from a previous relationship.

We’ve been TTC since October last year and I finally had a positive pregnancy test on Tuesday (a few days before my period due to symptoms) then I did another which was negative, which I understand does happen so decided to leave it a few days before retesting but I had the most heaviest period of my life (which was early and I’m never early, my periods are so regular and predictable) anyway this was followed by worse cramping I’ve ever had which lasted approximately 12 hours (I never cramp either), I can only presume I’ve had an early miscarriage…I’m devastated and so upset. Has anyone had the same experience as I?