Stressed and frustrated...

I've been off of my BC since July in order to try to conceive.  Since then my periods were only off by a couple days and then a couple weeks. All pregnancy test were coming back negative. NOW I haven't had one since January. Went to the gynie today got my annual stuff done. All ok. And even their urine test came back negative. My doc didn't seem too concerned to even recomend a blood test. (Can I go to any lab and get it done myself without a script?) I have although, gained some weight since being off of the pill (coincidence or not...) and have been reading about that maybe hindering conception along with PCOS. I just can't wrap my brain around all of this. I know everything happens for a reason but, I'm ready for another. My son is going to be 7 next month and I'm having some serious baby fever... Ugh.