In the past, I've always known that I was pregnant really early (before I was due to start). With my first daughter, I was pretty thin when I got pregnant, so I started showing really early. It was a bit later with my second kid. The third time I was pregnant I busted out the maternity clothes really early (partially because I was just in need of a wardrobe boost).
This time, I didn't even know that I was pregnant until I was over 9 weeks. Since I didn't know I was pregnant, before then I was still doing everything as normal (including riding my bike most days pulling my kids behind me in their bike trailer). My normal clothes fit like normal. I was a bit annoyed that I was doing all of this cycling without seeming to lose weight, but otherwise it was fine.
Even after I found out, I was pretty pleased that my normal clothes still fit. We're not really planning on telling people until after the 12 week scan, so I was hoping not to wear maternity clothes until then. So I was getting ready this morning and told my husband how glad I was that all of my clothes still fit me just fine. My jeans were getting a bit snug at the front and a bit loose at the back (I guess the cycling did something after all). I go to put on my jeans, and the first pair (my tighter pair) won't zip up. Serves me right for being proud. Overnight I can literally feel a difference in the shape of my stomach. Most of my normal clothes are still fine, but as I'm just going to be at home today I went ahead and pulled out my maternity jeans.
The only problem is that my maternity jeans are still too big and so they keep sagging down. I've spent more time yanking up my jeans today than doing just about anything else. I wish I could find a belt.