DO u have 2 be ovulating???

Hi just a Q for u all....
Not TTC at the min as waiting for some treatment, but will be soon....
However when i say this we did have unprotected sex lastnight, i was worried about what to do... but i took a didgital ovulation test thing this morning and it said im not ovulating, so does this mean that i can not get pregnant?
I have a baby of 7 and 1/2 months, and also suffer from PCOS when i got pregnant with my daughter, i came off my pill had my initial blead and then got pregnant, so i never had another period etc and didnt use the ovulation testing kits either....
I came off my pill in December (to get ready for when we try again) had an initial blead and no period since (which i know is normal) but im a bit confused about the hole thing really, as i thought if u weren't having periods u wouldnt get preg, (but last time i did), hope this makes some sort of sense.
But mainly i just want to know if im not ovulating then i cant get preg can i???