Late Ovulation or Pregnant?

(Long story, sorry, LOL!!) I have NEVER spotted when I ovulate, never gotten nauseas, bad headaches ect. I can't remember exactly when I had my last period. I know it started during the 28Nov-1Dec sometime. Normally I get sore boobies a week before my period is due. I have a normal 28-ish day cycle. My husband and I have NOT had sex (before this month) for several months!! Life, being sick, moving, ect, whatever. We had sex on the 8th of December. On the 16th I had some red smear of blood when I went to the bathroom. Just that one time. I thought OK whatever. My period would NOT be due till close to the end of the month, even if it started on Dec 1st! Later on that day I remembered about "implantation bleeding", when the egg attaches to the uterus, yadda yadda. So I checked out my guesstimated ovulation time for December and it was anywhere between December 8-16 but NOT after. But almost every website I checked out said spotting only 8 days after sex was not possible and couldn't be implantation bleeding. That it only occurs within a max of 9 days before your period. Well even if I didn't start my period till Dec 1st, my period wouldn't be due till the 25th-29th which would kinda make implantation bleeding on the 16th very unlikely. So I thought, OK well then no big, nothing to worry about. I went out just in case and got a pregnancy test and ovulation kit. I used the test on the 18th and was negative. I used the ovulation test on each day starting the 18th (cause it's kinda fun peeing on these things) and it said no ovulation each day. I figured, "well duh, it would be negative because my ovulation was supposed to be around the 8-16th. Not after. Then yesterday I kept getting nauseas, headaches and really peeved off. My uterus feels irritated and kinda tight and for three days a occasional pin prick feeling and more feeling drained. I had one more ovulation pee stick and I was bored last night, so I peed on it. It turned positive. WTF?!?! The 20th is pretty LATE for me to be ovulating!! Even IF my period started on the 1st of Dec!! I shouldn't be ovulating this late in the month!! So I googled ovulation symptoms and you can have nausea, headache and grumpy with it. So I was like, OK fine, my cycle is a little screwy so whatever, that must be it. But then I read on the ovulation website that IF you are pregnant the ovulation test will be positive! Because it also picks up the HCG hormone. My boobies are not sore however, just a general icky feeling. So one of two things are going on. #1- My body is being a total effing B and giving me pregnancy symptoms the first time in MONtHS that me and my H had sex, but it is actually due to me ovulating and not pregnancy!!! #2- I actually got pregnant the FIRST time in months that me and my H have had sex! Even though it took 6 YEARS of trying to have our son!! So I took another ovulation test today and it was negative. :P What the heck is going on?