Concerned: Supposed to be TWW.

So my husband and i finally decided to start TTC for baby No.1 I got off the pill two months ago with no luck. I know to expect my natural cycle to be off until I get into my natural rhythm. With that being said I'm supposed to be midway through my two week wait and I started to spot very heavily last night/evening I have a lack of words and I'm totally caught by surprise.

What does this mean? Advice please, it will be very much appreciated! I would like it understand what exactly is going on with my body.