Is spotting at 4dpo too early for implantation? 12dpo now.

I'm 12dpo now but I spotted on 4dpo,it was brown and lasted 3 days.. I can't sleep at night,feeling naseous at night,back pain and ovary pain. Now I'm having period like cramps but I'm not due for my period till another 4 days.. Could've it been too early? It wasn't a period and I never spotted in my life..