missedpills unprotectedsex earlybleeding pregnacy symptoms

hi. ive been on yaz bc for 11 months now. and on Jan 22nd and 23rd i missed my pills. me and my boyfriend have sex almost everyday and he ejaculates inside me . we didnt use any back up protection when i missed my pills then on the 27th of january i started bleeding but different from my normal period. it only lasted 3 days and was dark red for one day and then the other 2 days it was brown (could this be implantation or because i missed pills) . i took my last pill on the 30th. and by my schedule i should start my period by the 2nd or 3rd of Feb.
i have had the following symptoms:
nauses( and for the past 2 days very sick after i eat)
bloating
low back aches
moodswings
craving salty foods
headaches
and very very tired

i have taken 2 hpts and both came out negative. they were realy cheap ones fromthe dollar store though(could this effect accuracy, or could it be still too early?)

also i have never had breakthrough bleeding in the 11 months that ive been on bc.
and i have missed pills before( a longg time ago) and never bleed from it.

SOMEONE PLEASE HELP!
do you think im pregnant or paranoid?

I am also experiencing something somewhat similar. I have been taking the same form of birth control for the past 3-4yrs. I was a week into my pack of pills and forgot to take my pill (sunday), so I took 2 the following day (monday). Tuesday I started spotting, and noticed that this spotting was more like a light day period. I am still bleeding and have been experiencing abdominal and back pain. The pain can change from mild to pretty severe. I noticed breast tenderness too. I have missed pills before and this has never happened to me. I had unprotected sex with my boyfriend the 3rd day of my previous period and that saturday before I missed my pill.

Can someone please help us figure out whats going on?