[sera300]

She needs to read. Predicting ovulation is very difficult usually if a woman has a 28-30 day cycle, you figure the next expected period, then count back 14 days which is the estimated time for ovulation during this time you can become pregnant a few days before and a few days after. I would not try it unless you are both willing to chance a pregnancy. Spermicides are okay but not reliable even when used in conjunction with abstinence during the ovulation. It can happen at any time, and although rare an egg can be released during a period and fertilized right after her period. Look at barrier methods combined with a spermicide--diaphragm, cervical cap. Read Brandyes sticky on BC failure rates. I would not do this unless you don't mind becoming parents real soon.
Here is her info...
If 100 women have regular sex for a year, the number who become pregnant will be:

No protection - 85

Withdrawal - 40

Condoms alone - 10

Spermicide alone - 15

Hormone (pill, etc) - 3

Condoms plus spermicide in the vagina - 3

IUD - 4

This all assumes protection, properly used, every time. The spermicide on the condom should be considered lube. There is not enough to really protect against pregnancy. There should be 150 mg's of spermicide in the vagina and the normal dose (applicator, sheet, tablet, suppository) of whatever you are using will provide this.