is quite unlikely. It's much more likely that you didn't ovulate this month, and that's the reason that your period hasn't come.
I'm pretty sure that this period was going to be late, whether you had sex or not. If you got pregnant during sex, that results in a late period 2 weeks following, not in the next week after sex.
Most likely the reason for not ovulating is a combination of stress and weight gain. Either one alone can result in a missed ovulation
, and the two together are more likely to cause it.
So I wouldn't worry about pregnancy. The only way you could be pregnant is if your ovulation was delayed so long that you ovulated around the time you had sex. This would be rare.
Most likely your period will come sometime, although it's anybody's guess just when. If you don't get a period for 2 weeks after the sex, then do a pregnancy test
, just to be sure. It takes about 2 weeks after conception
for a pregnancy test to reliably be positive.
Meantime, I would work on the stress and weight gain, partly so this doesn't happen again in the future. Exercise, good nutrition, sufficient sleep are all important.
Your previous unusual last period is also suggestive that your cycles are getting thrown off, probably also by the stress and weight gain. Best wishes.