I'm 6 days late for my period. i've taken 5 tests all negative. i had a baby 5 months ago. could i be pregnant again?

Pregnancy: If you have been sexually active you may be. You didn't say when the tests were taken. Consider retesting in a week or less if still no period. There are other reasons for missed periods besides pregnancy. Reasons for missed / late period include: an anovulatory cycle in which no egg is released, marked v or ^ in weight; eating disorder; Over-exercising (endurance athletics), stress, travel, etc.

Can retest next week: Pregnancy unlikely, but can retest next week. Home tests are very accurate and not affected by foods, herbs, common illnesses, sexually transmitted diseases, or medications. A correctly done urine test gives a reliable result 3 weeks after sex (3 weeks after when conception might have happened). If done sooner, a positive result is likely real, but a negative result may be due to testing too soon.