I had a ridiculously easy pregnancy and didn't even know or suspect I was pregnant until the beginning of my second trimester.  In my case, I was on Seasonale and didn't get periods for months at a time, so I couldn't rely on missing periods to tell me I was pregnant.  Plus, I didn't get a minute of morning sickness during pregnancy, either (some women don't).    However, during the second trimester, you go from normal-looking to distinctly pregnant (like, an unambiguous baby bump).  At that point, it's obvious you're pregnant.  You can't wear your normal clothes anymore, for example. For the record, I never felt miserable when I was pregnant--I definitely never felt "shitty"--though I was definitely more tired in the last trimester.