What Does Negative UPT With Stomach Cramps Indicate?

on sunday 18th december i started getting really bad stomach cramps i was having a period sat the time but have never previously experianced pain like this before. On the following monday the cramps were even worse and my lower abdominal was very tender to touch feeling really hard on the inside. On the tuesday i saw my gp and suggestedd that i may be pregnant even though i had just finished my period which might i say lasted 4 days longer than it usually does, nevertheless i did a pregnancy test which showed that i was not pregnant! woke up the next day and the stomach pains bloatedness and tender stomach had disappeared on to come back again today! monday 27th December oh i forgot to mention also that ive also had hot and cold fevers the day before the bad cramps.