Needing advice

Ok I feel this could be a long post so sorry in advance.

My period was due on 3rd and I got rather hopeful when it didn’t come immediately, however by dinner (evening) I started spotting very lightly and was quite a dark brownish type colour. I continued to spot yesterday but that finished/dried up last night and I’ve had nothing today. I did a test thinking this could have been implantation bleeding that came back negative.

Should mention, mild sore breasts, that feel rather heavy when I remove my bra, headache from hell yesterday and today. And I’ve also woken today with what feels like a cold coming on.

Have also been feeling sick on and off for over a week now, and unless I’m eating or drinking the sickness past couple of days has been a constant.

Should I wait a couple days and retest, or should I visit a Gp, as I’m concerned that if that bleeding wasn’t implantation then it was not a normal bleed as I would normally bleed for 4days, light to mid flow type bleeding.

Any advice would be appreciated..... help