Every single symptom you can imagine is a sign of early pregnancy. I say this as a person with an exceptional imagination. If you can dream it, it happens to someone in the early stages of their pregnancy.
In the window between my pregnancy attempts, and the time when I can test, every symptom means something. I decided to test this theory by entering random symptoms followed by "sign of early pregnancy." I typed in ringing in the ears and nose bleeds. I haven't had either. Both, according to the internet, can be signs of early pregnancy.
I have gotten more jaded about thinking I'm pregnant as we've been trying. I've also stopped letting myself google symptoms (except for blog research). The first month we tried I was totally sure. I was sure because of my poops and feeling dizzy all the time. I won't get into the poops but let's just say they were atypical. Let's face it, if I had a kid for every time I had atypical poops I would have thousands of children. That would be a child for every single time I ate beans. I was dizzier than usual but maybe I just needed a sandwich, or one less turn on the tire swing.
The next month I was convinced I was pregnant because I was having weird dreams. That's also a sign, in particular weird sex dreams. It's hard to know where the line is for "weird" sex dream, but in at least one of the dreams I had crossed it FOR SURE.
One month I got a monster pimple. I am talking the Mount Everest of the pimple world. It was so big I was worried it would leave negative space in my face when it erupted. Glad to report that didn't happen but pimples are also a sign of pregnancy.
The other thing about early signs of pregnancy is that a lot of them are also things that happen right before your period. A common one is swollen breasts but my breasts do that every month. Mood swings and bloating are also signs of pregnancy. Basically the lead up to your period is one big trick into fooling you you've conceived. I get it. It all has to do with hormones and the same hormones are involved in both processes. It would be great if instead of period symptoms when we were pregnant our bodies... (here I was going to write examples of other symptoms, that would be different than period symptoms, but every symptom I could think up is already a "pregnancy symptom").
To be totally honest I did find one symptom not linked to early pregnancy, which was "sudden fear of spiders." Though that search did lead me to read an interesting article about how arachnophobia may develop before birth in crickets. This is not so relevant to my life or theoretical baby but independently fascinating.
The onset of arachnophobia is out, but a sudden fear of heights? Can be a sign of early pregnancy. I'm serious.