I'm confused 🤔

So tomorrow I will be 10 weeks, and my due date is 8-8-18. Everyone keeps asking how am I this far along and only due in august. Saying the dates don't add up. I feel like they're suggesting I either don't have my dates right or I'm lying. I feel like there's something to do with the way they date things from the day of your last period. And everyone is just noticing because everyone knows august is the 8th month of the year, so in their mind I should barely be a month. I don't know why it bothers me when people ask me... 😡