If everything goes according to plan, SegWit should activate within 48 hours from now
Not exactly. Within 48 hours BIP91 will start to be enforced, and any miner not signalling for segwit (bit 1 per BIP141) will have their blocks ignored by BIP91 enforcing miners. After 95% of blocks in a single 2016 block retarget period signal for segwit, it will be locked-in. Then, after an additional 2016-block retarget period, segwit will finally actually activate. It will probably be the last week in August before segwit actually activates.