Advice

Help! I have a question.. hopefully you guys can help me! Yesterday I went to the midwife for the first time and she determined that I am 8 weeks and 4 days (today 5 days) pregnant. Now April 22 was the first day of my last period and I had light bleeding on May 18. This was probably an implantation bleed. Now these dates don't match my estimated due date of January 22. I remember having sex on March 16. But is it possible that it was the right time then or is that moment too long ago? Thanks in advance!