Well, I am sorry to tell you this but your friend is wrong about not having sex until the month ends. It is totally safe to have intercourse ANYTIME! Unless of course it is painful for you during certain times of the month. Also, cervical mucus is good-means you are ovulating and the pain is so common and normal as well so no worries :-)
Hope that helps!
Its very common to feel "twinges" or ovulation pains on either side of your abdomen.. a lot of women feel this and it can be a useful tool too!!! i'd add Ovulation predictor kits as well, just to make sure your getting LH surges (which causes ovulation) If you have stretchy cervical mucus that is great! Typically you are fertile until the last day of that type of cervical mucus... And intercourse is perfectly ok throughout your cycle, in fact you want to make sure you don't stop too soon... so defintely have intercourse even after you think you've ovulated, just to make sure! There are a few thoughts that orgasms cause uterine contractions would could interfere with implantation, however it seems to be poorly studied from what i've found... and implantation tyipcally doesnt' happen until 7-12 days after ovulation anyways.. GOOD LUCK!