Not pregnant 😔

So like I said before I had what I thought was implantation bleeding about 6 days ago, I've also experienced mild cramping mood swings and the taste of metal in my mouth yesterday ( not taking any meds). Yesterday I thought I saw the faintest line on my pregnancy test, even my boyfriend saw it...... but this morning with fmu nothing 🥺. I feel devastated because my boyfriend and I have been trying so hard to ha baby #2 but nothing's working for us...