Hi, Lorah, please give more information. Like this:
First day of last period ______________
Periods come every ___ days (or, cycle length varies)
Sex with guy 1 December 23
Sex with guy 2 December 26
Any other sex around that time and dates
First ultrasound date ____________
Estimated due date given from that ultrasound ________
Any changes in estimated due date based on other ultrasounds: