Hi I'm 9 days late but I am also breastfeeding my one year old. At 7 days late I got a negative test but I have nausea and frequent urination with no uti. Today I noticed a very scarce light brown color on my underwear. Would this be my late period or imp

Cannot tell yet. A person can only tell she HAD implantation spotting in hindsight, after confirming a pregnancy. A urine pregnancy test, done correctly, gives a reliable result 3 weeks after sex (3 weeks after when conception might have occurred) or 1 week after missing a period. If done sooner, a positive result is likely real, but a negative result may be due to testing too soon, and thus lead to a repeat test.