If your symptoms were from pregnancy, your test would be positive. It's that simple. By the time hCG is high enough to cause symptoms, it's well past the point where a home urine test would detect it.
Does it mean you absolutely aren't pregnant? No. You could've ovulated late (or not ovulated at all yet, both of which are completely normal coming off the Pill). But it still means the current symptoms are not from pregnancy. Like late/no ovulation, they're incredibly common side effects of normal hormone changes, particularly when coming off hormonal birth control and readjusting.
Test again in another week. If you remain sexually active, keep testing once a week or so until you get a period or a positive. If it's been at least 3-4 weeks since the last time you had sex and you still get a negative, no need to keep testing.