Okay, so you have right censored observations. Then we are back to the first part of my first comment which is to use PROC ICPHREG to fit the interval censored model to deal both with your discrete stages as well as the censoring. See the example in the Getting Started section of the ICPHREG documentation. Your data will have multiple observations for the multiple stages for each subject. The left and right time variables in the MODEL statement will define the stages using intervals of (0, 1), (1, 2), (2, 3), ... , (6, .) where the last interval is for those subjects who don't get pregnant. In the MODEL statement, specify the BASE=DISCRETE option. You can add a BASELINE statement with the SURVIVAL= option (and LOWER= and UPPER= options if desired) to obtain estimates of the survival curve(s) over time.
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