Low potassium

Hey all. I am currently 31 weeks pregnant and I have had low potassium levels several times this pregnancy. I did stay sick to my stomach until 19 weeks and at 19 weeks my potassium was 3.3. It then dropped to 2.4. I was given potassium by mouth for 2 weeks and then rechecked my levels and they were fine. I had them redrawn today and it’s back down to 3.1.. I haven’t had any more vomiting or anything like that. Any idea what could be causing it? I’ve also made an effort to increase my dietary potassium intake.