Can this be cancer?

Hi yes im so scared right now if anyone can help please do thank you

my symptoms are
frequent urination
constipation
for 4 months midcycle pain usually 2weeks before my period last for 3days or more

had an us with my obgyn last feb15 26. (no constipation yet just frequent urination)
found right adnexal mass complex in stucture
size 2.4 x 2.5x 2.4 cm
she gave me antibiotics for a month and to come back after my period

march 2 right adnexal mass still present (no constipation just frequent urination)
complex in structure size 2.05x 1.65 cm
my obgyn want a follow up after 6months she said that its not cancer

after a week i started having a hard time passing stool up to now
with frequent urination

what should i do?
does this sound like cancer?
im planing to have another scan after my period and ask for a 2nd opinion from a gyn onc
but im just so scared

[lot12]

Oh i forgot to add im 27 yrs old
I have two kids 8 and 3
Last sept 2011 i had a laparatomy to take out a benign ovarian cyst it was just fluid filled