Are the chances of getting pregnant better if you have sex in the morning?

No. There is not a lot of difference in conception rates by time of day. Nighttime is theoretically better, since there is more time at night for sperm to pool at the cervix, and less chance of loss after standing. Men tend to have a higher urge in the morning, since testosterone levels rise early in the morning. Do it when the mood suits you, at least every other day near ovulation.
Anytime is good! There are many myths about ideal timing of sex for conception. This is one of them. You should have sex when you feel like it. Healthy couples will tend to have sex at their most fertile times. This can be any time of day and can be many different times during the cycle.