this is what fertility friend says..
The dotted lines on your chart for the coverline and ovulation detection mean that there is something about your data that puts your ovulation date in question. Usually this is because one or more of your non-temperature fertility signs do not confirm the ovulation date that your temperature would suggest. This may not mean anything significant for you, especially if your thermal shift is clear. Sometimes your fertility signs just do not all match up to show a perfectly correlated picture. In most cases, the detection is still quite reliable, but it means that you have to keep looking at your chart and your fertility signs and have intercourse if you see any signs of increased fertility.
When the lines are dotted and the thermal shift is not clear or dramatic, it is especially important to keep having intercourse since it is possible that you are still waiting for ovulation. If a more likely ovulation date becomes apparent later, the software will usually adjust the detection automatically.