May one get engaged during the 3 weeks?

One may get engaged during the 3 weeks and it is even permissible to have a celebratory seudah until Rosh Chodesh. From Rosh Chodesh Av, although engagements are permitted, only light refreshments may be served. Music and dancing are forbidden from the 17^th of Tammuz until after Tisha B’Av, even at an engagement.

My moustache is getting really long, may I trim it?
If your moustache interferes with your eating then you are permitted to trim it.

Am I allowed to comb my hair during the 3 weeks if I know some hair will come out?

Yes. This is permitted even during the week of Tisha B’Av.

May I get my Sheital cut in the 3 weeks?
Yes, until the 9 days.

May I make a shehecheyanu on a new fruit during the 3 weeks?
One should ideally refrain from making a shehecheyanu on a weekday but may recite it on Shabbos. If the fruit will not keep until Shabbos, one may recite the brocha and eat the fruit.

During the 3 weeks, may a pregnant woman or ill person eat a new fruit during the week or must they also wait until Shabbos to make the brocha?
A pregnant woman or ill person is permitted to eat a new fruit during the week, though they should not recite a shehecheyanu on it.

My wife just gave birth to a baby girl. May we recite shehecheyanu even though it’s in the 3 weeks?
You may recite the brocha of shehechayanu on a baby girl even after Rosh Chodesh. Mazel Tov!

May I wear my new suit during the 3 weeks?
For the first days of the three weeks, new clothes that require a shehecheyanu may be worn on Shabbos and shehecheyanu is recited. From Rosh Chodesh, however, they should not be worn.

May I buy new clothes during the 3 weeks?
Clothes which do not require a shehecheyanu may be bought and worn until Rosh Chodesh. Clothes which do require a shehecheyanu may be bought until Rosh Chodesh but it is preferable to refrain from doing so.

May I buy a new car in the 3 weeks?
If you would not say shehechiyanu you may buy until the 9 days. If it is for business purposes you may buy even the 9 days.

May I listen to music in order not to get depressed or calm me down?
If not listening to music will genuinely effect your emotional stability, then it is permitted.

May I listen to music in order to help me exercise?

If it is necessary, then this is permitted until Rosh Chodesh.