First of all, I suggest you to undergo one home pregnancy
test or a blood test
for beta HCG
to check pregnancy status at the earliest.
Second thing, chepalexin is very much safe in pregnancy and can be taken in the treatment of UTI.
Take healthy diet with vitamins & folic acid
supplements, avoid stress/ tension, drink plenty of water/ juice, maintain genital hygiene properly and take adequate rest.
Be well & take care.