Thanks for the query.
test kits can give false positive results.
For more details:http://srsree.blogspot.in/2012/06/causes-of-false-positive-pregnancy-test.html
Menstrual cycle can undergo changes depending on many factors which can influence the hormonal
balance like stress and strain, weight changes, recent illness, thyroid
hormonal fluctuation, anemia etc.
So for confirmation of pregnancy you can go for blood test
for pregnancy which will give accurate result compared with urine test.