Implantation bleeding or late period?

For the last couple of weeks i have been feeling 'odd'. Suspecting i may be pregnant but i also know the mind plays tricks on you. Im not trying to fall pregnant but somewhere along the way i may have missed a pill or taken one late.
The list of is as follows.
-Gas- for a week straight i have been constantly farting, burping, bloating after ANYTHNG i attempt to eat. To the point its beyond a joke.
-Tired- I have never been one to sleep during the day and lately all i want is to nap, or go to bed by 8.
-Cramping in my lower tummy, somewhat like period pain (which i very rarely experience).
-Slight pain in my lower back.
I am currently on the pill 'Yaz' and i had started taking my period pills and it ended up being late a week, (usually it starts the day of the period pill..and will have brown discharge couple days before.)
About a week ago i had light pink discharge after sex. I began bleeding red blood yesterday, once in the morning when i went to the toilet, and then a little watery brown discharge later..not very much and again today a little heavier and this time darker with more of a brown tinge.
Any feedback would be great from anyone whos been in my situ, does this sound like implantation bleeding or just a weird period..
I will take a HPT but ill wait a little longer.. x