Wondering mommy

Does anyone ever wonder if they are still pregnant? I’m 16 weeks and some days I just don’t feel pregnant. This is my second child and I guess i assume I should feel things a lot quicker than my first. I thought I felt movement at one point but then that stopped. Some days my breasts are still tender some days they aren’t. Some days I feel fine. Some days headaches and sickness are my best friends! I go to the OB tomorrow to check the baby and find the gender. I’m hoping all is well. Just seems 4 weeks between visits is too long! Lol