12 DPO BFN.. Could I have tested too soon?

So today I am 12 DPO (I believe) this is my first month trying to conceive, although last month my husband and I did not use protection I was not tracking or trying in any other way. This entire week I have felt nauseated, had sore breasts and nipples, heart burn, stomach pain, cramps, and a mild head ache every day. I do normally get bad PMS symptoms but never like this. I took this test today and got a BFN glow predicts my AF will come this coming week but I do have an irregular period at times and wasn't tracking last month so that's not 100%. 
Curious if anyone has tested at 12 DPO (or even latter) and gotten a fales positive?