Sooo weird

Soooo, I completely missed my last period, no blood at all..a bit of spotting around the time that would be considered implantation bleeding. Other than that no signs of period, I'm supposed to have ovulated yesterday but that didn't show, and my next period is in 13 days. I went to my obgyn which they said with now and compared to when I was pregnant with my now 5 year old daughter. With her my body didn't show a positive until after my second missed period (around 2 months along and I took a test 3 weeks after the second missed period) they think this is going to be the same case so I guess if I miss my next period they're just going to do an ultrasound but for now I'm advised to not drink, take meds that could be harmful to a baby and etc... has anyone else had this happen?? My doctor doesn't seem too concerned and told me some women don't produce the pregnancy hormone right away and it's not uncommon.. I'm confused, am I just broken??