Ultrasound and Conception

[bz3125]

I am 20 years old and currently 22 weeks pregnant. On February 26th I found out via ultrasound that I was 7 weeks and 3 days pregnant. My last (irregular) menstrual cycle was on Jan. 6th, 7th, or 8th (don't remember 100% due to the fact it was only 2 days long, but a constant light flow)I have about 4 questions 1) How accurate are ultrasounds at 7 weeks? 2)Could emergency contraceptive taken on Dec. 22nd effect the next menstrual 3) When would conception have occurred, December or January and 4th) Would the E.D.D still be viable even though my period was irregular or could that "period" have been implantation bleeding?

[momma2be]

Hi I'm 18 weeks pregnant.Just had my ultrasound last weeks july 2...The midwife told me I was measuring 17 weeks, which means i conceived in march.. I think im just really going crazy!!!! I hope and think this is not a january baby, right?....I had my period in january and february, took a pregnancy test in the beginning of march and came out negative... Went to my ob appt april 9th and told my doctor i  didnt get my period in march and started getting almost like menstrual cramping for the past week.....I just need to know if ultrasounds are really accurate?......PLEASE HELP!!!!!!

[bz3125]

Well my previous menstrual was on Dec. 10, 2006, and then the following menstrual after the e.c was on Jan. 6th, which was on time but irregular. The beginning of February I did experience some brownish red spotting when I used the restroom. So i am confused. The ultrasound taken on Feb. 26, 2007 dated me at 7 weeks with a due date of 10-13-07, so when at least and maximum would conception have occured. And how far off can ultrasounds be? Sorry i just need to clarify