I am 5 days late of my period, i was supposed to get my period last thursday and have usually had a normal cycle of 28 days. i had pms/pregnancy symptoms yesterday such as lower back pain, nausea, and constipation. all my test came back negative, even blo

Late periods: It depends on how old you are or if you have had intercourse within the "danger" period, but yes missed periods for females almost always warrant a pregnancy test. Spotting can also mean hormonal changes which may be natural as you age, or related to a number of other factors, including stress, nutritional variation, anemia, etc. Recommend you visit an MD clinic to be checked out.

Which tests?: How many and which tests did you have for ALL of them to come back negative? The only test needed to be done is a home pregnancy test (HPT) when your period was missed (4-5 days ago). You can wait 1 week & repeat the HPT. If that's negative then, see your OB/GYN. if 2 HPT's are negative (assuming they were done properly) the chance you're pregnant is very low.