One day period?

It's been a little over 6 months since I lost my baby at 13 weeks. My husband and I started trying again as soon as we could. My periods started up normal after the loss. Well in December I had an odd period, I had some bleeding for a day, not enough to fill a pad or tampon. Then for two days I had very light spotting that quickly went away each time I checked. I count it as my period because I've heard implantation is rare and it was the day I was suppose to start. I did take a test a few days after just in case and it was a BFN. I am now suppose to start again in 4 days but the past week and a half I have been so neaseous, following the last few days I have been throwing up and with major heartburn starting last night. I haven't had heartburn since my last pregnancy.. Has anyone experienced anything similar and still got a bfp?

I am going to wait to see if my period comes this month to test again but I was just curious