Ok I had my last period on dec. 19 and I had sex on dec. 31 jan. 1 and 2.. I also had sex while on my period on dec 19 and 20.. I had protected sex about 2 days before my period... I found out I was pregnant on jan. 14.. I had an ultra sound on april, 28 and the baby measured at 19.4 weeks.. At the time according to my lmp I was 18.6 weeks. I went to the Dr. Today and he told me i'm 22 weeks but according to ultra sound and that tape measure thing. Where they measure your stomach i'm 23 weeks..So what does this mean i'm having a big baby or did I not coniceve when I thought I did... Dec.31, my Dr. Hasn't changed my due date sept. 26.. I"m just confused b/c by my measurements when I count back 23 weeks it lands before my period even started.. Has anyone else had there measurements be this way.. According to this information when would you say I concived.....