pinkish fluid after sex

It's probably just your hymen tearing. Sometimes women can bleed during sex, especially the first few times.

If you miss your period next time, take a test according to the package directions about WHEN and HOW to take it. If you take it too early, you can get a false negative. Resist the urge to take it right away. Some tests aren't accurate for more than a week after your missed period.

You need to start protecting yourself. Even if your boyfriend is a virgin, too--you can get the same STDs from oral sex as you can from vaginal sex, so if either of you have done that before, even a little, you could have been exposed. You need to use condoms EVERY SINGLE TIME YOU HAVE SEX--oral or vaginal. Seriously. We get too many posts like this from both girls and guys. Sex is so much more enjoyable when it's not stressful. Using protection eliminates so much stress about both pregnancy and STDs.

If you want to use a condom, but your boyfriend doesn't like to, just tell him that he obviously doesn't like having sex either. Because that's the only way he's going to get it. He'll get used to it.