If you have a test, the only question will be how much you've wasted on it: a quid or less from Poundland etc or nearly £20 (some of the more expensive brands) because you're not going to get pregnant from this.
You are doing stuff that you're not entirely comfortable with though, so even if you're not planning to have penis in vagina intercourse yet, it would be worth talking to your GP about contraception options.