Why this, why now?

My senior year of high school in April 2016 I was on the pill, but due to various mental health conditions I had a great deal of trouble taking it at the same time every day. I thought I was fine, but then my period was a week late. Then, I did get it, although it was short and I passed a large chunk of grey tissue. I took a pregnancy test afterwards but it was negative. I can't help but think I was pregnant for a very short amount of time, as I was having unprotected sex with my then-boyfriend. Ever since then I've felt like there's something missing, and even though I've never wanted kids I miss the baby that I could have had. I want a little one to love and hold and protect, even though I'm not yet 20, single, living with my parents, have multiple serious mental health problems, and am trying to get my life back together after getting kicked out of college due to rock bottom depression. I can't be the only one who feels this way. I don't know how to feel because I know now is not the right time whatsoever. Ugh. Rant over