Frequent Urination, HPT, UTI Negative, Abdominal Pain, Late Period. Pregnant? What Should I Do?

Hi, My troubles started over a month ago, I was having trouble keeping down food of an evening and frequent urination . I went to see my local gp who did a urine test for pregnacy and UTI both came back negative, he then sent me for an internal and normal ultrasound to check for appendicitis . This also came bak negative. The vomiting stopped about two weeks ago but now I have abdominal pain coming and going everyday and am still needing to pee all the time! I will empty my bladder and not even 10 mins later need to go to th loo again! I m going back to my gp next week and he will probably do more tests but now my period is 5 days late also, I m wondering if I may be pregnant and it was just to early to come up in the test as it was done 1 day before my last period.