Help me, now i'm really confused

So 3 weeks ago on thursday my period was due, she still has not shown her face. I did several home pregnancy tests all of which there was a faint line. After 2 weeks of waiting patiently and no period I went to visit the gp and explained that I was at that point 2 weeks late for my period and that I had had several faint positives. She did a test in the surgery and it came back negative, she requested that I have some bloods done to check all my hormone levels. They have rung me this morning and everything was normal and the blood pregnancy test was negative 😭 I am incredibly confused as I am 3 weeks late. I have a normalish cycle, which can range from 36 days to 43 days. I am now on day 56 of my cycle. The only other time I have been this late was when I was pregnant with my daughter. She wants me to go for an ultrasound to see whats happening in there 😢 I can't help but feel a little sad for something that I had convinced myself was finally happening after a year of actively ttc