1st month ttc, baby #1

Ok so from 4dpo I had every sign apart from morning sickness that Made me think is this is we got it on the first cycle? But then on 18th November I took a test 4 days before af due and got a bfn, 19th November I went to the loo and the tissue had some light pink fluid on it, to light to be af and she isn't due until 22nd November, any one else had this and resulted in getting a bfp