Chance of pregnancy?

Ok so dec 4 was the last time I had sex and he precum near me and tease me by putting his penis on me and not all the way in I bleed a week or so after but it wasn't like my normal period it was bright red and didn't hurt as much and it usually does and now I'm late and no cramps at all like I usually would before my period but for the past two weeks or so I have been so nauseous and I've gained quite a bit of weight and belly is rounding (I might just be fat 😂) but am I paranoid or pregnant