6 weeks, maybe? Maybe TMI?

So I felt like I was pregnant 2 months ago, but I started a period on June 4. It was super light.. I was supposed to start again on July 4. I didn't. But 2 days later I spotted a little bit I thought it was a period so I bought tampons but that was the only time I bled. The next day I bought a test and it came back positive. I went to a pregnancy center to confirm the test and they estimated I was 6 weeks, by my LMP. Something tells me I'm further, or there's something to this. I'm already feeling way fatter and just off. Maybe I'm just thinking that, this will be my 2nd baby. My first is almost a year old. Any comments on this? Thoughts?