brown discharge

so me and oomf had sex for the first time last night, it's been awhile for me (about 2 years) he fingered me a lot and tried with 3 fingers (it really hurt) and then we had unprotected sex only for alittle. this afternoon i noticed a brown color watery discharge in my underwear, i thought it was my period but i stuck a finger to see and it was still brown, i'm not ovulating and i don't think there was pre cum because it was 5 mins, should i be nerveous??