Why am I still cramping?

TTC #2. O'd on July 7 period due around the 22nd. Puts me at 6 dpo today. I have had cramps since O and this has never happened to me. I usually cramp a day or two before O and on O day a little worse. I'm also very gassy since then too. I tried to link the two but where I'm cramping doesn't seem to be the right area for gas? Woke up with a massive headache, breasts and pelvic region  have been sore as well.