Implantation or PMS?

All symptoms started today at 8DPO: -low abdominal cramps, similar to period cramps but more intense -intense lower back pain that spreads to thighs -nausea including being sick in my mouth (gross) -bloating -fatigue -migraines (I do suffer from these a lot but this started 2 days ago) -heartburn (I never get this) I’m reluctant to test as it’s too early.. usually I don’t get period pains, just light cramps sometimes - period is not due for 7 more days so even still, it’s pretty early for me to be getting PMS symptom. Had unprotected sex roughly 36 hours prior to ovulation this cycle.