Regarding Periods. Chance of pregnancy?

I and my gf had intercourse on 25th Nov and on 26 Nov she had taken unwanted 72. Her Last periods was on 12 Nov-17 Nov. From 12-17 Dec she had bleeding the first two days was a heavy bleeding then she had less bleeding. After 21 dpo her upt is negative. On 17 dec (3week) First  Ultrasound report seen minimal endometrium collection and then doctor repeat the second ultrasound which was normal and Beta serum HCG is was less than 0.10. Now no need to worry. Her next period will come on time. Is there any chance of any kind of pregnancy or ectopic pregnancy. The last beta HCG was done on 22nd December which showing less than 0.100. She again did upt on 28th November showing very little faint line on T it's goes after sometimes. No intercourse happen after 25th November. So there is no chance of pregnancy?