what could it be? 3 dpo

Laurie • 23. Québec canada 🇨🇦. Speaks french,english. Married since september 2016. Pregnant with baby #1.Mila💕 october 2017.
3 dpo and I have cramps since this morning  and sore boobs. Normally the cramps begin few days before af like 12-14 dpo and my boobs never hurt. what could it be?