Trying to concieve after stillborn in 2015

I ovulated 2 days after I went off of my cycle. Todays makes 7 dpo. On my 4 dpo i started having early pregnancy symptoms. My breast and nipples were hard and sore and in yesterday 6 dpo I was cramping really bad in my lower abdominal. I took a pregnancy test today and got a bfn. I can't lie im pretty upset but i do know thatit is still early. Af isn't due to come again until the 25th of April. When should i test again