Some lubricants contain spermicide, and it is obvious that couples who are trying to get pregnant should not use those. Lubricants that are strictly meant for lubrication should never be used as contraceptives they do not prevent pregnancy as such. But, studies have shown that lubricants like KY jelly do in fact hinder the movement of sperm. Cervical mucus is so thick that it stops sperm from reaching the cervix at some points during the menstrual cycle, and lubricants can have much the same effect. The conclusion?
If you are trying to conceive, using a lubricant is not advisable. There are some sperm friendly lubricants on the market that are fine to use if you really feel the need to lubricate things and are hoping for a baby. Those include:PreSeed Yes Baby ConceivEase Zestica
Stick to those, or ask your pharmacist for information and advise if need be. On top of that, I should mention that vaginal dryness or a lack of tell-tale fertile cervical mucus during a woman's ovulation may actually indicate that there is a fertility issue going on. If you are using lubricants for any purpose other than personal preference, it may help to see a doctor about your issues. And, if you enjoy using special lubricants to spice your intimate life up (like those made by Durex) than it may be good to reserve those for the luteal phase of your cycle, when you can no longer conceive anyway. Remember, sperm can survive inside the female body for around five days, so you can consider your fertile window to start at five days before your expected ovulation.