Im so sorry your feeling like this, your right to be worried. Dont think twice about contacting gp again and again and again. When it comes to your health there is no back up - they could even do an urgent referral to gynaecology -  not sure? As im up in scotland and nhs is kind of separate to nhs england. 
 

im not any better unfortunately, im worse than i was pre surgery.  Having a really uphill battle. I did have my ca125 done, once in dec when the nhs originally found it and once after i has been to private gyn (saw private one on a Saturday and my gp did my ca125 on the monday) both times they were 16 i think. 
 

its so hard as you could literally drive yourself mad with worry , i know i am currently. It diesnt help that i am also going through complaints procedure etc

the GP could even offer you some pain relief for the interim until they know whats going on? 
 

sending you lots of positive thoughts , I completely understand how frightening this is xx