I just got a positive on a pregnancy test this morning and I am 2 weeks pregnant. I had my last period starting September 17, 2015, but the app says I am 11 weeks pregnant. I used the regular <a href="https://play.google.com/store/apps/details?id=com.glow.android">Glow app</a> to teach my periods and ovulation and when I marked that I was pregnant today, it went all the way back to when I started using the app and made that my conception day which is wrong. What am I doing wrong?