I had sex wit my ex-boyfriend after my menstral flow(23rd-27th dec) on the 4th of jan and on the 6th of that same jan i had sex with my boyfriend now am six weekr five days pregnant and i don't know who the father is pls help me
Your period STARTED on 23 December?
You had sex on 4 Jan, day 12 of your cycle with your ex.
You had sex on 6 Jan, day 14 of your cycle with your bf.
You will need a DNA test. There is NO way around it. You will normally ovulate between days 11 and 16 of your cycle and sperm can survive up to about 5 days. Timing wise, it's just about perfect for either of them to be the father.
Was the date calculated by ultrasound? Ultrasound dating is approximate. Most doctors base dates on your LMP because most women know when that was, as you do.