I am on my 29th day of my menstrual cycle and...

Treatment of delayed period?
First of all we should be sure that you are not pregnant by doing the B-HCG test which is the hormone of pregnancy as it is more accurate than strip test. If the hormonal test is negative and the period still delaying, then further assessment will be needed. Physical assessment by gyne and obs doctor as well as running some tests as will be mentioned down below. In case you have hormonal disturbances OCP could be used. In case there is Polycystic ovarian syndrome OCP, metformin and spironolactone could be prescribed. Furthermore, hyperprolactinemia and thyroid problems should be excluded. In addition to that, try to avoid stressful situations as much as you can, having enough rest and sleep as well as to follow a healthy diest regimen.

Diagnosis?
History and physical exam done by doctor. CBC done routinely to check your hemoglobin level as well as WBC. B-Hcg test to exclude pregnancy. TSH, prolactin to exclude hormonal problems. Abdominal ultrasound to exclude POS.

Causes of delayed period?
1. Pregnancy
2. Thyroid disease
3. POS
4. Primary ovarian failure
5. Vigrous exercise
6. life stress
7. Using of OCP for a while
8. others

Advice:
it's recommended to see a gyne & obs doctor for further assessment.