Why There Is No Headache When I Have Meningioma?

i have been diagnosed with meningioma 3.3*3.1*2.9.my neurosurgeon has told me that i need a craniotomy to get it removed.It is in the rt temporal lobe.I have no head ache since last 3 weeks.Prior to that i had continous headache for 45 days and used to be on painrelivers every 4 - 5 hrs.i wonder why there is no head ache now? i dont take any meds now.