possible chemical pregnancy, emotional mixed feelings

Feeling confused, lost and just shit and sad at the same time.. so we weren't trying for a pregnancy but I ended up being 14 days overdue for period, in that time I had gone from freaking out about a possible pregnancy to actually liking the idea of maybe being pregnant, I did a test a week late and it was negative so I thought it might be a bit too early so did another one a couple of days later and it came up a faint positive, I was so confused as I was excited but thought not to get my hopes up, a few days later I did one and it was negative, I had so many symptoms and I was completely convinced I was pregnant but then a few days later AF came, lighter than usual but I ended up passing some pink brown tissue and clots and after that I was convinced I definitely was not pregnant. But then I found something about decidual bleeding, so had a glimmer of hope and tested after my period and it was a bfn.. I've lost all the symptoms, am completely emotional and sad, crying at everything.. I feel completely stupid as it wasn't planned and I wasn't 100 percent sure if I was pregnant anyway and women go through so much more heartache than this, has anyone been through something like this? Is there anyway to know if I was pregnant and it was a chemical pregnancy as such? I am also RH negative so if it was I am wondering if I would need to get an injection?