I had sex 3 weeks ago Sunday the 13th will be 4 weeks. I took a pregnancy test mid day 2 days ago and it was negative. But I'm 7 days late I've been sick to my stomach feeling, headaches, tired, tender breast, and bloating, and my stomach is very hard (usually it's squishy but for the past week I will get random un godly cramps in my lower stomach like where my ovaries are. Is that a sign of implantation without bleeding ?