Trying to conceive

Hello po, March 24 pa po last period ko and until now wala pa ring period. Pang 13th day missed period ko na po. Too early pa po ba mag PT? Nung nag try po kasi ako ng 10th day missed period ko, negative naman result. First time ko po na delayed ng ganito katagal since regular po ako. Any advice po? Thanks in advance po.#advicepls