It's not like you're 8 months pregnant....

I'm 6 1/2 weeks and the nausea is real. It's constant. It subsides sometimes but for the most part I'm always struggling with it. I'm tired, physical activity makes me feel motion sick and I'm noticing the smallest smells that make it worse. My MIL makes the same comments all the time. " It's not like you're 8 months pregnant", "you're milking it" etc. My FIL does the same thing. She says I should be taking a dance class/ yoga class or go to the gym...but I have to pump myself up just to get to the grocery store. I've seen similar post about this subject. Why do we get dismissed during early pregnancy? Why do we have to be 8 months pregnant for people to take us seriously?