You can go on with your usual activity - you will know soon enough.. if you do think you might be - avoid alcohol and any other activity that could be risky to a baby until you know for sure.
The spotting you had on those days may have been ovulation spotting since this would have been time for ovulation.so i would suggest waiting until your period is due.
If you are trying to use the rhythm method do *not* get pregnant, why are you having intercourse during your ovulation days (typically around day 14 if you have a 28 day cycle)? If you're serious about using this method, I'd suggest buying the book, "Taking Charge of Your Fertility" so you learn how to chart your cycle and understand when you are most fertile...
As Melka said, you'll have to wait til you miss a period to test. Day 15 is way too early since you probably just ovulated then.
Congrats to you!
So you think I might still be pregnant? Should I be careful with anything I do? Or just go on with my exercise and day to day stuff as usual?
The earliest a HPT would be positive is maybe 5 days before your missed period. My was not positive until the 4 day before. I am 12 weeks. I would wait until you miss your period and then test again. Good Luck