Feeling uncomfortable lower abdominal!

Hi mummies, i tested positives and based on my first day of the last menses, I will be 5 weeks 4 days today. However, I keep feeling uncomfortable on my lower abdominal, feeling like you are having menses like that. Anyone experienced this before? I actually felt down when I mop the floor 3 days ago without knowing that I'm preggy, so kind of worry too. But the uncomfortable feeling is felt before the fall though. Thank you.